Synergistic Electron–Photon Effect over Engineered Pt–Cr Clusters Enables Sustainable and Sulfur-Resistant Methane Combustion

Efficient low-temperature catalytic combustion is paramount for CH4 abatement, yet its practical implementation is severely hampered by a persistent trade-off between high catalytic activity and robust sulfur resistance. Herein, we report a synergistic electron-photon strategy where Cr modification first precisely tunes the electronic structure of a Pt–Ti-based catalyst, creating an optimized catalyst foundation that is then powerfully leveraged by incident photon-assisted catalysis to optimize the reaction path. Specifically, Cr incorporation on Pt8Cr2/r-TiO2 engineered highly dispersed Pt–Cr oxide clusters with a unique interfacial synergy. Characterizations and DFT studies confirmed that these clusters feature significantly increased Pt4+ active sites stabilized by Pt–Cr electron transfer while also weakening the Pt–O bond and inducing abundant surface oxygen vacancies. These foundational electronic modifications by Cr greatly enhanced intrinsic low-temperature activity and, by inducing interfacial electron enrichment, suppressed SO2 adsorption. Critically, the subsequent injection of photons unlocked an exceptional photothermal synergistic performance. The T90 for CH4 combustion decreased by an additional 71.3 °C under the photothermal catalytic strategy. Photoassisted kinetic analysis and in situ DRIFTS revealed that photon irradiation substantially enhanced the chemisorption of CH4 molecules on the catalyst surface, significantly lowered the apparent activation energy, and altered the reaction pathway. Enhanced charge separation efficiency, facilitated by the engineered cluster-support interface, promoted O2 activation and established a charge barrier to repel SO2 species. Thus, through this synergistic interplay of atomic-scale electronic modulation and subsequent photon-driven enhancement, the Pt8Cr2/r-TiO2 catalyst exhibited remarkable stability, enabling sustainable low-temperature activity even under 200 ppm of SO2. This work provides fundamental insights into designing highly active, antipoisoning and noble-metal-reduced catalysts for challenging combustion reactions, paving new avenues for environmental catalysis technologies.