Cooperative Fe–Ti dual-metal sites for highly efficient photocatalytic non-oxidative methane conversion

Abstract

Selective methane conversion is a promising low-carbon technology, yet developing catalysts capable of effectively activating inert C–H bonds under mild conditions remains challenging. Here, we designed Fe²⁺–□–Ti⁴⁺ dual-metal-sites on the high-activity {012} facets of defective ilmenite (Fe_1−xTiO_3−x-NS). Mechanistic studies revealed that Fe²⁺–□–Ti⁴⁺ can be excited to form a long-lived Fe³⁺–□–Ti³⁺ active state, while surface lattice oxygen stabilizes the reaction intermediates during multistep elementary reactions. This bimetal–oxygen synergistic strategy significantly reduces the activation barrier for C–H bond cleavage to just 0.15 eV, fully blocks the over-dehydrogenation of methyl intermediates, and facilitates C–C bond formation, thereby achieving a favorable non-oxidative methane conversion rate that even surpasses noble metal-supported photocatalysts, with nearly 100% C₂₊ selectivity. This bimetallic-center construction strategy not only provides an efficient and economical pathway for methane conversion but also expands the boundaries of traditional photocatalysts, exhibiting high catalytic activity and product selectivity.