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Chinese Journal of Catalysis
2023, Vol. 46
Online: 18 March 2023

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Cover: Profs. Zhongmin Liu, Yingxu Wei and coworkers in their article on pages 11–27 revealed the contribution of hydrogen transfer (HT) reactions to the dynamic evolution of zeolite-catalyzed methanol and DME conversions, realizing the in situ quantitative monitoring of HCHO concentration in MTO. Dynamically evolving HT reactions as the hidden-line simultaneously occur and interplay with the main reactions of olefin generation as the open-line, constituting a complete dynamic reaction network for methanol and DME conversion.

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Novel mechanism for selective cracking of sugars on WO3 and its significance for biomass utilization Lercher Johannes A. 2023, 46:  1-3.  DOI: 10.1016/S1872-2067(22)64206-2 Abstract ( 425 )   HTML ( 31 )   PDF (1079KB) ( 361 )

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The future of organic electrochemistry current transfer He-Yang Zhou, Hai-Tao Tang, Wei-Min He 2023, 46:  4-10.  DOI: 10.1016/S1872-2067(22)64197-4 Abstract ( 533 )   HTML ( 35 )   PDF (1177KB) ( 493 )   The electrostatic attraction between electrons and nuclei is a fundamental force in electrochemistry. This force drives the interaction between electrons and nuclei, providing the potential for redox reactions. As a result, it is the basis of redox chemistry. In recent years, organic electrochemistry has made significant progress in oxidative hydrogen evolution coupling and sacrificial anode electroreduction, thanks to its efficient and environmentally friendly capacity to create reactive intermediates. This paper focuses on several areas in the field of electrochemistry, including optimizing electrode materials, developing new electrolytic catalysts, paired electrolysis, photoelectrocatalysis, bioelectrosynthesis, and artificial intelligence-assisted electrosynthesis. The aim is to optimize reaction mechanisms and explore interdisciplinary combinations.

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Hydrogen transfer reaction contributes to the dynamic evolution of zeolite-catalyzed methanol and dimethyl ether conversions: Insight into formaldehyde Shanfan Lin, Yuchun Zhi, Wenna Zhang, Xiaoshuai Yuan, Chengwei Zhang, Mao Ye, Shutao Xu, Yingxu Wei, Zhongmin Liu 2023, 46:  11-27.  DOI: 10.1016/S1872-2067(22)64194-9 Abstract ( 319 )   HTML ( 20 )   PDF (9920KB) ( 346 )   Supporting Information Formaldehyde (HCHO), generating from hydrogen transfer (HT) of reactant, is significant for autocatalysis initiation and deactivation in methanol-to-olefins (MTO), but hitherto, its evolution throughout the reaction has not been thoroughly revealed. Herein, by the established colorimetric analysis method, HCHO in the MTO and dimethyl ether (DME)-to-olefins (DTO) reactions over SAPO-34 was in situ quantitatively monitored, where HCHO was detected in slight and conspicuous amounts at initial and deactivation stages with semi-conversion, also when co-fed with water or high-pressure H2. We reveal the weak HT ability of DME relative to methanol, which enables prominent olefins-based cycle and suppresses reactant-induced HT and deactivation in DTO (which is critical for MTO). A complete dynamic reaction network is disclosed, constituting two simultaneous and interplaying pathways: the main reactions for olefin generation as the open-line and HT reactions as the hidden-line. Especially, co-feeding high-pressure H2 with DME capacitating a long-term and highly efficient operation of DTO by modulating the dynamic reaction network to a more moderate autocatalysis evolution, has great potential in industry application.

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A covalent organic framework inspired by C3N4 for photosynthesis of hydrogen peroxide with high quantum efficiency Chaochen Shao, Qing He, Mochun Zhang, Lin Jia, Yujin Ji, Yongpan Hu, Youyong Li, Wei Huang, Yanguang Li 2023, 46:  28-35.  DOI: 10.1016/S1872-2067(22)64205-0 Abstract ( 500 )   HTML ( 38 )   PDF (2057KB) ( 524 )   Supporting Information Carbon nitride (C3N4) has been the main research focus for photocatalytic H2O2 synthesis that may enable the on-site and on-demand H2O2 production under mild conditions. Its potential is unfortunately shadowed by the narrow light absorption and fast charge recombination. Building on the understanding of the inherent merits and pitfalls of C3N4, we here propose to assemble active heptazine motifs with functional linkers in ordered molecular frameworks for highly efficient photocatalytic H2O2 production. Herein, a heptazine-based covalent organic framework is synthesized via the Schiff-base reaction. It has enhanced light absorption and charge separation. When irradiated with visible light in the presence of sacrificial electron donors, the sample exhibits an excellent H2O2 production rate of 11986 μmol h-1 g-1 and an apparent quantum efficiency up to 38% at 420 nm, outperforming most organic or inorganic competitors in our best knowledge. Impressively, the catalyst can also endure long time operation that affords the linear H2O2 accumulation to a practically usable concentration.

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Surface-enriched ultrafine Pt nanoparticles coupled with defective CoP as efficient trifunctional electrocatalyst for overall water splitting and flexible Zn-air battery Zexing Wu, Yuxiao Gao, Zixuan Wang, Weiping Xiao, Xinping Wang, Bin Li, Zhenjiang Li, Xiaobin Liu, Tianyi Ma, Lei Wang 2023, 46:  36-47.  DOI: 10.1016/S1872-2067(22)64198-6 Abstract ( 256 )   HTML ( 14 )   PDF (5844KB) ( 408 )   Supporting Information Developing multifunctional electrocatalysts toward energy-related reactions could reduce the cost and improve the utilization efficiency of raw materials. Herein, defective CoP decorated with ultrafine Pt nanoparticles (Pt/d-CoP/NPC) with multifunctional electrocatalytic performances is prepared via facile pyrolysis and following chemical reduction process. The as-synthesized Pt/d-CoP/NPC owns high half-wave potential of 0.82 V for oxygen reduction reaction with excellent stability in 0.1 mol/L KOH. Density functional theory calculations demonstrate that the adsorption energy of *OO at Pt/d-CoP/NPC is stronger compared to Pt, yielding higher catalytic activity for ORR. Moreover, the resultant electrocatalyst possesses excellent catalytic activities with low overpotentials toward hydrogen evolution reaction (33 mV in 1 mol/L KOH, 6 mV in 0.5 mol/L H2SO4 and 70 mV in 1 mol/L PBS) and oxygen evolution reaction (320 mV) at 10 mA/cm2. Water-splitting and rechargeable Zn-air batteries assembled with the as-synthesized Pt/d-CoP/NPC as electrodes exhibit outstanding activity and long-range stability. Remarkably, sustainable energies and homemade Zn-air battery can efficiently drive the Pt/d-CoP/NPC electrolyzer with sumless hydrogen bubbles generated, verifying the potential applications for renewable energy storage.

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Dual-atom Co-Fe catalysts for oxygen reduction reaction Tianmi Tang, Yin Wang, Jingyi Han, Qiaoqiao Zhang, Xue Bai, Xiaodi Niu, Zhenlu Wang, Jingqi Guan 2023, 46:  48-55.  DOI: 10.1016/S1872-2067(22)64189-5 Abstract ( 592 )   HTML ( 24 )   PDF (3575KB) ( 483 )   Supporting Information Controlled synthesis of dual-atom catalysts (DACs) for heterogeneous catalytic reactions is vital but still demanding. Herein, we construct a novel dual-atom catalyst containing FeN3-CoN3 sites on N-doped graphene nanosheets (CoFe-NG), which exhibits remarkable catalytic performance with a half-wave potential of 0.952 V for oxygen reduction reaction (ORR) and shows higher endurance to methanol/carbon monoxide poisoning and better durability than commercial Pt/C. The assembled Zn-air battery with CoFe-NG as the air electrode delivers a peak power density of 230 mW cm-2 and exhibits negligible change in output voltage at 5 mA cm-2 for 250 h. Theoretical calculations reveal that FeN3-CoN3 sites on N-doped graphene exhibit lower ORR barrier than FeN4 and CoN4 sites, and the rate-limiting step on the former is the transformation of *OH intermediate to H2O, different from the transformation of *O to *OH on the FeN4 site and the transformation of O2 to *OOH on the CoN4 site.

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Unraveling the active states of WO3-based catalysts in the selective conversion of cellulose to glycols Yue Liu, Wei Zhang, Haichao Liu 2023, 46:  56-63.  DOI: 10.1016/S1872-2067(22)64187-1 Abstract ( 248 )   HTML ( 12 )   PDF (1307KB) ( 152 )   Supporting Information Tungsten-based catalysts, including crystalline WO3 and H2WO4, have been reported to be efficient for the selective cleavage of C−C bonds of sugar intermediates involved in the conversion of cellulose to ethylene glycol and propylene glycol in combination with hydrogenation catalysts under H2 atmosphere. However, there is still not a consensus on the actual states of these catalysts during the reaction. Herein, we demonstrate that both WO3 and H2WO4 tended to undergo reduction to hydrogen tungsten bronze (HxWO3) species in the cellulose reaction, consisting of H0.23WO3 and H0.33WO3, which were then re-oxidized to WO3 upon exposure to ambient air after the reaction. Both WO3 and HxWO3 were insoluble in water and acted as the heterogeneous catalysts in the cellulose reaction, as further validated by the strong dependence of the catalytic activity of WO3 on its crystallite size and surface area. Such identification of the heterogeneous HxWO3 species, albeit exemplified here only from the in situ reduction of WO3 and H2WO4 in the cellulose reaction, unravels the active state of the tungsten-based catalysts under reductive reaction conditions.

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Ru single-atom catalyst anchored on sulfated zirconia for direct methane conversion to methanol Hua Liu, Leilei Kang, Hua Wang, Qike Jiang, Xiao Yan Liu, Aiqin Wang 2023, 46:  64-71.  DOI: 10.1016/S1872-2067(22)64191-3 Abstract ( 264 )   HTML ( 8 )   PDF (2217KB) ( 286 )   Supporting Information The direct CH4 conversion (DMC) to methanol is a challenging topic. In this study, the Ru/SZ (sulfated zirconia) single-atom catalysts (SACs) were synthesized and utilized to the DMC to methanol under mild conditions (70 °C). The yield over the Ru/SZ SACs (18.32 µmol, TOF ≥ 80 h-1) significantly exceeded the sum of the yields over the SZ (0.67 µmol) and Ru/ZrO2 (0.29 µmol), indicating that a new active center was formed on the Ru/SZ SACs. Combined with the results of the 13CH4 isotope labeling experiments and various characterizations including the pyridine adsorption infrared spectroscopy, electron paramagnetic resonance and X-ray photoelectron spectroscopy, an unprecedented synergy effect between the single-atom and the super acid sites was pictured: The strong acidity of the Ru/SZ SACs could effectively promote the decomposition of H2O2 into the •OH, and the Ruδ+ (δ > 4) and the adjacent Zrγ+-•OH (γ > 4) could synergistically catalyze the CH4 to methanol.

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In-situ formation of electron-deficient Pd sites on AuPd alloy nanoparticles under irradiation enabled efficient photocatalytic Heck reaction Haifeng Wang, Fan Wang, Xiaopeng Li, Qi Xiao, Wei Luo, Jingsan Xu 2023, 46:  72-83.  DOI: 10.1016/S1872-2067(22)64192-5 Abstract ( 330 )   HTML ( 20 )   PDF (3268KB) ( 321 )   Supporting Information Plasmonic metal nanoparticles have emerged as important candidates for photocatalysis. Numerous studies have shown that coupling of a plasmonic component (such as Au) as the light energy harvester with a catalytically active metal component (such as Pd) to form hybrid or alloy structures could achieve enhanced catalytic performance. However, the microscopic mechanism relative to the multicomponent plasmonic photocatalysis is still elusive. Here, we find that the electron-deficient Pd sites (Pdδ+) on AuPd alloy nanoparticle were formed under visible light irradiation, which play a decisive role in the AuPd alloy nanoparticle photocatalysis. The in-situ formed Pdδ+ under irradiation offers ideal platform for the catalytic reaction which is comparable to that under thermal heating conditions (>100 °C). The AuPd alloy nanoparticles show excellent conversion and selectivity for visible-light-driven Heck cross-coupling reaction under ambient conditions. The combination of experimental and density functional theory results suggest that the photocatalytic Heck reaction proceeds via a new radical-based single-electron transfer pathway on the AuPd alloy, and the in-situ formed Pdδ+ sites ideally provided efficient catalytic sites for the activation of reactant with much lower activation energy barrier under irradiation. The present work sheds light on the new mechanistic understandings of bimetallic plasmonic photocatalysis.

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Bioconversion of methanol to 3-hydroxypropionate by engineering Ogataea polymorpha Wei Yu, Jiaoqi Gao, Lun Yao, Yongjin J. Zhou 2023, 46:  84-90.  DOI: 10.1016/S1872-2067(22)64195-0 Abstract ( 300 )   HTML ( 17 )   PDF (1056KB) ( 547 )   Supporting Information Methanol bioconversion toward chemical production can be helpful for carbon neutrality. Here metabolic engineering an industrial methylotrophic yeast Ogataea polymorpha was conducted for overproduction of 3-hydroxypropionate (3-HP), an important platform chemical, which can be used for production of special chemicals including acrylamide, acrylic acid, 1,3-propanediol, as well as biodegradable plastics. We developed several metabolic engineering strategies to optimize the 3-HP biosynthetic pathway and enhance the supply of precursors acetyl-CoA and malonyl-CoA, and cofactor NADPH, which enabled the 3-HP production of 1.45 g/L under batch fermentation and 7.10 g/L under fed-batch fermentation at shake flask scale, with a yield of 0.14 g/g methanol. This was, to our knowledge, the highest 3-HP titer from methanol and even one-carbon sources. This study demonstrated the potential of O. polymorpha as a cell factory for chemical production from methanol.

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Theoretical design and experimental study of pyridine-incorporated polymeric carbon nitride with an optimal structure for boosting photocatalytic CO2 reduction Chengcheng Chen, Fangting Liu, Qiaoyu Zhang, Zhengguo Zhang, Qiong Liu, Xiaoming Fang 2023, 46:  91-102.  DOI: 10.1016/S1872-2067(22)64159-7 Abstract ( 299 )   HTML ( 11 )   PDF (2785KB) ( 232 )   Supporting Information Herein, pyridine-incorporated polymeric carbon nitride (PCN) was explored for boosting photocatalytic CO2 reduction. First, theoretical calculations were performed on PCN models with pyridine molecules located at different positions to determine the optimal structure of pyridine-incorporated PCN with the lowest total energy, smallest bandgap, and most efficient CO2 adsorption and activation processes. Subsequently, pyridine-incorporated PCN with the optimal structure was prepared experimentally by copolymerizing urea and 2-aminopyridine (AP). A high CO evolution rate with a selectivity of 99.6% was achieved by combining CN-5%AP with a Co(bpy)2 co-catalyst, which resulted an apparent quantum efficiency of 2.86% at λ = 420 nm. The high performance of pyridine-incorporated PCN mainly originated from its strong CO2 adsorption ability and facilitation of the CO2-to-CO reduction reaction. This work paves the way for the precise design and preparation of photocatalysts with high CO2 reduction efficiency.

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Photocatalytic methane activation by dual reaction sites co-modified WO3 Keran Wang, Lei Luo, Chao Wang, Junwang Tang 2023, 46:  103-112.  DOI: 10.1016/S1872-2067(22)64169-X Abstract ( 227 )   HTML ( 12 )   PDF (2319KB) ( 291 )   Supporting Information Methane (CH4) upgrading into liquid oxygenates under mild conditions is of great significance to sustainable energy and clean environment, whilst holds great challenges of achieving superior activity and selectivity. Herein, tungsten oxide (WO3) modified with palladium (Pd) nanoparticles and oxygen vacancies (OVs) was employed as dual reaction sites to drive CH4 conversion with O2 at room temperature. Optimized Pd0.5-def-WO3 photocatalyst enables almost 33 times improvement in oxygenates production compared with WO3, with a yield of 7018 μmol·g-1·h-1, and a high selectivity of 81% towards primary products (CH3OH and CH3OOH), which is superior to most of the previous reported. In-situ XPS spectra proved Pd nanoparticles were the hole acceptors based on the shift of Pd3d to high binding energy under light irradiation. The in-situ solid-state EPR spectra demonstrate an enhancement of OVs signal which proves the role of OVs as the electron acceptors. Consequently, efficient charge separation has been achieved, contributing to the superior activity and selectivity for CH4 conversion.

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Promotion of dual-reaction pathway in CO2 reduction over Pt0/SrTiO3‒δ: Experimental and theoretical verification Zhuogen Li, Qadeer Ul Hassan, Weibin Zhang, Lujun Zhu, Jianzhi Gao, Xianjin Shi, Yu Huang, Peng Liu, Gangqiang Zhu 2023, 46:  113-124.  DOI: 10.1016/S1872-2067(22)64175-5 Abstract ( 154 )   HTML ( 10 )   PDF (16443KB) ( 232 )   Supporting Information The H2 evolution is generally considered a competing reaction in photocatalytic CO2 reduction reaction (CO2RR) using H2O as the proton source. However, the reducing gas H2 generated from H2O splitting can be the proton source in CO2RR under the enhanced dynamic role of the thermal effect. The reverse water gas shift (RWGS) reaction, a CO2 hydrogenation reaction, should occur in photothermal environment owing to thermodynamically and kinetically favorable. Herein, nanostructured metal-semiconductor contact consisting of Pt nanoparticles (NPs) supported on SrTiO3‒δ nanosheets with rich oxygen vacancies (Pt-OVs-STO) was constructed for investigating its feasibility and efficiency in the RWGS reaction under photothermal effect. Our experimental results substantiate that the H2 generated by H2O splitting effectively contributes to the RWGS reaction over Pt-OVs-STO system. The Pt0 NPs not only efficiently facilitate surface charge transfer, but also lower the energy barrier of the O‒H bond breaking, H2 releasing, and RWGS reaction, thereby showing an outstanding CO2RR performance. The strong interaction between the Pt0 NPs and SrTiO3‒δ has been extensively demonstrated by a series of experimental characterizations and density functional theory calculations. This work elucidates the relation between H2 evolution and RWGS reaction over Pt0/SrTiO3‒δ structure in photothermal catalytic CO2RR using H2O as the proton source and provides new perspectives for subsequent CO2RR.

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Highly active and stable MoS2-TiO2 nanocomposite catalyst for slurry-phase phenanthrene hydrogenation Chenggong Yang, Donge Wang, Rong Huang, Jianqiang Han, Na Ta, Huaijun Ma, Wei Qu, Zhendong Pan, Congxin Wang, Zhijian Tian 2023, 46:  125-136.  DOI: 10.1016/S1872-2067(22)64184-6 Abstract ( 167 )   HTML ( 5 )   PDF (2444KB) ( 191 )   Supporting Information MoS2-TiO2 nanocomposite catalysts with Janus structure were synthesized via facile one-step solvothermal method. X-ray diffraction, high resolution transmission electron microscope, NO chemisorption and X-ray photoelectron spectroscopy were applied to characterize the composition and nanostructure of the MoS2-TiO2 nanocomposite catalysts. Experimental results revealed that the MoS2-TiO2 nanocomposite catalysts with Janus structure were composed of MoS2 layers (few stacked layers of 1-3 and short slabs of 2-10 nm) and TiO2 nanoparticles (10-15 nm), which have strong MoS2-TiO2 interaction with transferring electrons from TiO2 to MoS2. Catalytic performance of MoS2-TiO2 nanocomposite catalysts for phenanthrene hydrogenation was investigated and compared with that of MoS2 catalyst in an autoclave reactor with high temperature and high pressure. The phenanthrene conversion over the MoS2-TiO2 nanocomposite catalyst with MoS2 content of 15.0 wt% (MoS2-TiO2-15) can reach 91.6%, which was much higher than 50.4% for MoS2 catalyst and 76.8% for conventional supported MoS2/TiO2-15 catalyst. After 7 cycles of phenanthrene hydrogenation reaction, the phenanthrene conversion over MoS2-TiO2-15 nanocatalyst remained at 68.6%, while the phenanthrene conversion over MoS2 catalyst was reduced to only 25.4%. The MoS2-TiO2 nanocomposite catalysts exhibit significantly enhanced catalytic activity and stability for slurry phase hydrogenation. The enhanced catalytic activity originates from the exposure of abundant coordinatively unsaturated Mo atoms. The enhanced stability results from the Janus structure with stable MoS2-TiO2 interaction and Mo-O-Ti bonds, which anchor MoS2 layers on the surface of TiO2 nanoparticles to avoid the curling, folding and agglomeration of MoS2 layers. This is an important finding on slurry phase catalytic hydrogenation performances of MoS2-based nanocomposite catalysts with Janus structure. Shedding light on the research of Janus nanocomposite catalysts in catalytic hydrogenation is significantly crucial for the development of effective and stable hydrogenation catalysts.

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Enhanced performance of Pd-[DBU][Cl]/AC mercury-free catalysts in acetylene hydrochlorination Xingzong Dong, Guangye Liu, Zhaoan Chen, Quan Zhang, Yunpeng Xu, Zhongmin Liu 2023, 46:  137-147.  DOI: 10.1016/S1872-2067(22)64204-9 Abstract ( 238 )   HTML ( 7 )   PDF (3514KB) ( 206 )   Supporting Information Compared with the rapid deactivation of the Pd/AC catalyst, an eco-friendly Pd-[DBU][Cl]/AC ([DBU][Cl], 1,8-diazabicyclo[5.4.0]undec-7-ene hydrochloride) catalyst with enhanced stability was synthesized and applied in the hydrochlorination of acetylene. The Pd-20[DBU][Cl]/AC catalyst exhibits 96.7% acetylene conversion and 98.9% selectivity of vinyl chloride within the 24 h evaluation under the conditions of T = 180 °C, GHSV(C2H2) = 360 h-1 and V(HCl)/V(C2H2) = 1.2. The enhanced stability of the Pd-[DBU][Cl]/AC catalyst is attributed to the prevention of the reduction of Pd(II) to Pd(0), the inhibition of the formation of coke deposition on the catalyst surface, and the reduction of the loss of Pd species during the reaction. TPD characterization and DFT theoretical simulations confirmed that the PdCl2-[DBU][Cl] complex has stronger adsorption of HCl and weaker adsorption of C2H2 and C2H3Cl compared to PdCl2. Furthermore, the catalytic mechanism of acetylene hydrochlorination over the PdCl2 and PdCl2-[DBU][Cl] site was put forward based on theoretical simulations. The good activity and stability of Pd-20[DBU][Cl]/AC in the 60 h lifetime test indicates that it is likely to be a promising alternative to HgCl2 catalysts.

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Boosting 5-hydroxymethylfurfural electrooxidation in neutral electrolytes via TEMPO-enhanced dehydrogenation and OH adsorption Hongfang Wang, Leitao Xu, Jingcheng Wu, Peng Zhou, Shasha Tao, Yuxuan Lu, Xianwen Wu, Shuangyin Wang, Yuqin Zou 2023, 46:  148-156.  DOI: 10.1016/S1872-2067(22)64203-7 Abstract ( 519 )   HTML ( 26 )   PDF (3141KB) ( 385 )   Supporting Information 5-Hydroxymethylfurfural (HMF) electrooxidation in neutral conditions is a promising strategy to suppress the formation of humins and corrosive effects on electrochemical devices. However, scarce studies have been reported in neutral media due to the deficiency in electrophilic oxygen (eg OH‒) required for the activation of HMF. Herein, 2,2,6,6-tetramethyl-piperidine-1-oxyl (TEMPO)/Co3O4 was utilized to co-catalyze HMF in neutral media, successfully achieving 2,5-furandicarboxylic acid (FDCA) with yield > 99%. It was found that TEMPO could promote HMF dehydrogenation to 2,5-diformylfuran (DFF) and simultaneously activated water via hydrogen-bonding interactions. As a result, the formation of OH* in neutral electrolytes was favored, which was absorbed by electrogenerated active Co species to facilitate subsequent conversion of formyl-group-involved intermediates to FDCA. This work provides a current understanding of the catalytic mechanism for HMFOR in neutral media and guides the design of highly efficient electrocatalysts for biomass upgrading.

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Bismuth vanadate: A versatile heterogeneous catalyst for photocatalytic functionalization of C(sp2)-H bonds Fan-Lin Zeng, Hu-Lin Zhu, Ru-Nan Wang, Xiao-Ya Yuan, Kai Sun, Ling-Bo Qu, Xiao-Lan Chen, Bing Yu 2023, 46:  157-166.  DOI: 10.1016/S1872-2067(23)64391-8 Abstract ( 167 )   HTML ( 15 )   PDF (2102KB) ( 279 )   Supporting Information Bismuth vanadate hydrothermally synthesized at 180 °C and then calcined (BiVO4-180) is a versatile and stable heterogeneous photocatalyst for the functionalization of diverse C(sp2)-H bonds under ambient visible-light conditions, with a series of functionalized compounds, including tetrahydroquinoline-succinimide-fused heterocycles, tetrahydroquinolines, 3-(p-(N,N-dimethyl)ben- zyl)indoles, α-aryl α-amino acid esters, and thiocyanated/vulcanized/selenated (hetero)aromatics, synthesized in good yields (79 examples, including modified drugs and dipeptide esters). BiVO4 photocatalysts are advantageous because they are recyclable, inexpensive, air-tolerant, and highly efficient, which are typical characteristics required to overcome the shortcomings of homogeneous photocatalysts.

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S-scheme heterojunction of ZnCdS nanospheres and dibenzothiophene modified graphite carbon nitride for enhanced H2 production Han Li, Shanren Tao, Sijie Wan, Guogen Qiu, Qing Long, Jiaguo Yu, Shaowen Cao 2023, 46:  167-176.  DOI: 10.1016/S1872-2067(22)64201-3 Abstract ( 327 )   HTML ( 18 )   PDF (4957KB) ( 417 )   Supporting Information g-C3N4-based photocatalysts with an intramolecular donor-acceptor structure still suffer from inadequate visible-light absorption and severe charge recombination. Constructing S-scheme heterojunction is a promising approach to address these issues. Herein, ZCS (ZnCdS nanospheres)@DBTCN (g-C3N4 modified by dibenzothiophene groups) S-scheme heterojunction photocatalyst was synthesized through a self-assembly approach. The ZCS@DBTCN material showed a superior photocatalytic H2 production activity of 8.87 mmol g-1 h-1, which is 3.46 and 2.55 times that of pure DBTCN and ZCS, respectively. This enhanced photocatalytic performance could be ascribed to the synergistic effect of intramolecular internal electric field and S-scheme heterojunction, which boosts the separation and transport of photogenerated carriers within the molecular framework and at the interface, and preserves the maximum redox capacity of the spatially separated electrons and holes. Moreover, the S-scheme charge migrate mechanism of ZCS@DBTCN was strongly evidenced by the in-situ irradiated Kelvin probe force microscopy and in-situ irradiated X-ray photoelectron spectroscopy. This study provides a protocol for designing g-C3N4-based hybrid photocatalysts with high charge separation efficiency and excellent photocatalytic activity.

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Effect of palladium chemical states on CO2 photocatalytic reduction over g-C3N4: Distinct role of single-atomic state in boosting CH4 production Qian Li, Qijun Tang, Peiyao Xiong, Dongzhi Chen, Jianmeng Chen, Zhongbiao Wu, Haiqiang Wang 2023, 46:  177-190.  DOI: 10.1016/S1872-2067(22)64199-8 Abstract ( 220 )   HTML ( 17 )   PDF (6044KB) ( 376 )   Supporting Information Cocatalyst decoration has been recognized as an effective strategy in photocatalysis, yet the critical role of sing-atomic state on CO2 photocatalytic reduction, distinguished from the oxide and elemental states, remains a mystery hitherto. Herein, single-atom Pd (Pd-SA), Pd oxides (PdOx), and Pd nanoparticles (Pd-NP), were homogeneously anchored on g-C3N4 (CN) to investigate their CO2 reduction behaviors under visible-light irradiation. Performance tests showed Pd species decoration improved the CH4 production of CN, with Pd/CN-SA exhibiting the optimum yields (2.25 μmol g-1), markedly higher than that of PdOx/CN (1.08 μmol g-1) and Pd/CN-NP (0.44 μmol g-1). After comprehensive mechanism analysis with various characterization techniques, in-situ DRIFT spectra and DFT calculations, it was found that the conducive activation of CO2, negative conduction band potentials, and excellent •H utilization efficiency, collaboratively contributed to the superior CH4 production of Pd/CN-SA. Despite the larger electron density of Pd/CN-NP and PdOx/CN, the moderate reduction ability of their photogenerated electrons restricted the further reduction of adsorbed CO2 species and CO intermediate, limiting the enhancement of CO2 reduction activity. Furthermore, the CH4 evolutions of Pd/CN-NP and PdOx/CN were also limited by the poor •H supply and inferior •H utilization efficiency, respectively. It is expected that the effect of chemical states, especially the critical role of single-atomic state, revealed in this work can inspire the rational design of more advanced photocatalysts for CO2 reduction.