Experimental investigation of dry reforming of methane over Ni/CeO2 catalysts in a kW-scale solar reactor: enhanced performance of porous structures11The short version of the paper was presented at CUE2025, Kitakyushu, Japan, July 18–22, 2025. This paper is a substantial extension of the short version of the conference paper

Solar-driven dry reforming of methane (DRM) represents a promising approach for converting greenhouse gases into syngas using renewable energy. Despite its potential, this technology is currently plagued by low solar-to-fuel conversion efficiency, limited syngas yield, and difficulties in scaling up, with most investigations remaining at the laboratory scale. In this work, a kilowatt-level solar DRM reactor system was developed with feed gas flow rates on the order of liters per minute, which marks a significant step towards its practical application. We synthesized two types of Ni/CeO2 catalysts, particle and porous, and comparatively evaluated their performance. The results demonstrate that the porous catalyst bed offers significant advantages in gas production performance, temperature distribution uniformity, and thermal management capability. These improvements led to an increase in the solar-to-fuel conversion efficiency of the solar reactor from 10.37% to 26.10%. Under variable operating conditions, the porous catalyst achieved a peak solar-to-fuel conversion efficiency of 33.26%. The key pathways of energy utilization and loss were identified via the energy analysis under optimal conditions, and the strategies for improving the energy efficiency of solar-driven DRM under large-scale conditions were proposed. These findings provide important insights for the design of efficient solar thermochemical systems.