Insights into the role of S-Ti-O bond in Titanium-Based catalyst for photocatalytic CH4 reforming: Experimental and DFT exploration

Given the increasingly severe climate and energy crises, this paper proposes the concept of “room-temperature solar-powered CH4 reforming”, intended to achieve carbon emission reduction and efficiently use carbon-containing resources. However, traditional semiconductors as catalysts have some problems, such as few catalytic active sites and fast recombination of photogenerated electrons and holes, resulting in low efficiency of photocatalytic CH4 reforming. For this reason, a series of doped catalysts X-TiO2 (X = Br, N, and S) are prepared by introducing nonmetallic elements into the TiO2 lattice to construct oxygen defects. Notably, the CO yield of the S-TiO2 catalyst was 1048μ mol g−1, 65 times higher than the catalytic performance of bulk TiO2. Based on the functional density theory (DFT) calculation, the interaction between the S active site and the performance of photocatalytic CH4 reforming with oxygen defects is discussed in detail. The synergistic effect of the S site and the oxygen defect has been shown to rapidly activate C = O and C-H bonds at room temperature. Finally, based on the tracer experiment and DFT calculation, a possible mechanism of photocatalytic CH4 reforming at room temperature is proposed. This work provides a new research direction for achieving carbon neutrality at room temperature and a feasible technical scheme for the large-scale application of photocatalysts.