Oxidation-Enabled Assembly Forms a Diatomic Catalyst for Propane Dehydrogenation

Abstract

The influence of trace oxidizing cofeeds on reshaping the catalytic microenvironment under reducing conditions remains largely unexplored. Here, we show that cofeeding trace CO2 or H2O with C3H8 constructs dual-atom sites for propane dehydrogenation, circumventing their reduction-induced aggregation that plagues such catalysts. The oxidation of In species gives rise to In3+ single atoms anchored by Si defects and then Rh3+ single atoms linked by framework oxygen, which together assemble diatomic sites with the structure of Z2[RhH] in a RhIn/S-1 catalyst. The catalyst with Rh loadings of merely 0.02 wt % exhibits an unprecedented performance with ∼75% C3H6 yield (near equilibrium), a space-time yield of 1729.1 molC3H6 gRh–1 h–1, and stability for 1000 h on-stream without regeneration, outperforming most of the state-of-the-art catalysts. Single-atom Rh3+ synergizes with atomically dispersed In-coordinated framework oxygen to facilitate C–H cleavage. This work reveals the hitherto unrecognized role of trace oxidizing cofeeds under reducing conditions and offers a promising strategy of oxidation-enabled assembly to design active sites extending to other catalytic processes.