Dynamic Light Regulation of Surface CO Coverage Enables Efficient Low-Temperature RWGS on Electron-Rich Pt

Abstract Surface poisoning by strongly adsorbed intermediates severely limits the efficiency of heterogeneous catalysts, yet dynamically regulating adsorbate coverage under reaction conditions remains highly challenging. Here we report that light irradiation can dynamically regulate CO surface coverage on electron-rich Pt-MoO 3−x catalysts and thereby promote the reverse water–gas shift (RWGS) reaction under low-temperature conditions. Consequently, the Pt-MoO 3−x catalyst exhibits markedly enhanced catalytic activity under full-spectrum illumination compared with dark conditions at identical catalyst temperatures. In situ XPS measurements reveal illumination-induced electron enrichment of Pt sites, indicating interfacial charge redistribution across the Pt–O–Mo interface. The continuous-flow CO-DRIFTS experiments simulate a CO-supplemented environment relevant to RWGS catalysis, revealing a pronounced illumination-induced decrease in the steady-state surface CO coverage, thereby dynamically maintaining the availability of active sites in a product-rich environment. Complementary adsorption–purge DRIFTS experiments further confirm the regulatory effect of light irradiation on chemisorbed CO species. Theoretical calculations bridge these findings and indicate that this robust electron-rich state reshapes the Pt–CO electronic interaction, fundamentally weakening the adsorption and alleviating CO poisoning. This effect cannot be attributed solely to photothermal heating. This work establishes light-mediated dynamic regulation of surface adsorbate coverage as an effective strategy for mitigating catalyst poisoning and enhancing heterogeneous catalytic reactions.