Abstract: Nickel-based catalyst samples prepared by the plasma reduction method and thermal method were used to make catalytically activated absorbers, and their activity for solar CO₂ reforming with CH₄ was tested using a laboratory-scale receiver-reactor with a sun-simulator. The results showed that the catalytically activated absorber of Ni/MgO-Al₂O₃ reduced by plasma had the highest activity at low temperature. Under the conditions of average ?ux density of 61 kW/m² and gas hourly space velocity of 36 dm³/(g·h), the CO₂ and CH₄ conversion was 54.5% and 72.7%, respectively, and the chemical storage efficiency reached 42.8%. The X-ray diffraction and transmission electron microscopy results indicated that the catalyst reduced by plasma exhibited higher dispersion of nickel and smaller crystal size than the catalyst reduced by the thermal method. The addition of MgO enhanced the basicity of the support and reduced the probability of carbon deposition on Ni/MgO-Al₂O₃.

Key words: plasma, methane, carbon dioxide, reforming, light irradiation, nickel-based catalyst, magnesium oxide, alumina