Highly Efficient and Selective Light-Driven Dry Reforming of Methane by a Carbon Exchange Mechanism

Dry reforming of methane (DRM) is a promising technique for converting greenhouse gases (namely, CH₄ and CO₂) into syngas. However, traditional thermocatalytic processes require high temperatures and suffer from low selectivity and coke-induced instability. Here, we report high-entropy alloys loaded on SrTiO₃ as highly efficient and coke-resistant catalysts for light-driven DRM without a secondary source of heating. This process involves carbon exchange between reactants (i.e., CO₂ and CH₄) and oxygen exchange between CO₂ and the lattice oxygen of supports, during which CO and H₂ are gradually produced and released. Such a mechanism deeply suppresses the undesired side reactions such as reverse water-gas shift reaction and methane deep dissociation. Impressively, the optimized CoNiRuRhPd/SrTiO₃ catalyst achieves ultrahigh activity (15.6/16.0 mol g_metal^-1 h^-1 for H₂/CO production), long-term stability (∼150 h), and remarkable selectivity (∼0.96). This work opens a new avenue for future energy-efficient industrial applications.