Photo-thermal coupled single-atom catalysis boosting dry reforming of methane beyond thermodynamic limits over high equivalent flow

Abstract

Driving dry reforming of methane (DRM) reaction by photo-thermal catalysis is a more gentle, efficient and environmentally friendly process than the traditional thermal catalysis. However, the process still lacks efficient catalyst and clear reaction mechanism. In this paper, we developed a Ru1/Mg-CeO2-NR single-atom catalyst (SAC), of which the molar fraction of syngas under photo-thermal catalysis (PTC) conditions could exceed the thermodynamic equilibrium limit of the same temperature in dark condition even at high equivalent flow rates, while achieving a molar level syngas formation rate (0.56 mol·gcat−1·h−1 for H2 and 0.85 mol·gcat−1·h−1 for CO) at only 500 °C. Besides, the electron transfer path of Ru-O-Ce and its promoting effect on RDS of DRM reaction were determined by operando experiments, and the in-depth mechanism of photo-thermal synergistic catalytic reaction was also illustrated. Finally, the superiority of the Ru1/Mg-CeO2-NR SAC configuration was investigated by density functional theory (DFT) calculation and the reversible structural evolution of Ru-O-Ce to Ru-Ov-Ce was verified, which provided the efficient and stable coordination environment for PTC-DRM reaction.