Ultrahigh efficiency CH4 photocatalytic conversion to C1 liquid products over cheap and vacancy-rich CeO2 at 30 °C

Abstract

Direct CH₄ conversion to value-added liquid products is an effective strategy to solve both energy and environment crisis. So far, CH₄ photocatalytic conversion faces the problems of complex and costly catalyst preparation, and low liquid product yields/selectivity. Herein, we show the preparation of CeO₂ with large quantities of surface oxygen vacancies via simple calcination, which served as a high-efficiency catalyst for CH₄ conversion at 30 °C, with the yield rate and selectivity of C1 products reaching as high as 3.88 mmol (g_cat h)⁻¹ (space time yield of 928 g (kg_cat h)⁻¹) and 97.73%, respectively. High turnover number of 463 was achieved during 8 h, which largely outperforms that of previous reports. Moreover, the catalyst exhibits excellent recyclability. The plausible reaction mechanism was studied using in situ FTIR, XPS, EPR, radical scavenger experiments, and DFT calculation. This work demonstrates an excellent catalyst that can be easily prepared in the batch mode for highly efficient CH₄ conversion, which will greatly promote developments in this field.