High entropy assisted platinum single atoms for photothermal green syngas production with high CO2 utilization efficiency

Abstract

Reverse Water Gas Shift reaction (RWGS) could convert CO2 as green syngas, which is limited by the low CO2 utilization rates. High temperature could promote the CO2 conversion rates of RWGS, but almost all catalysts are unstable and inactive for RWGS at high temperatures. In this study, we synthesized two-dimensional high-entropy oxide to stabilize Pt single atoms (Pt@CeYLaScZrOx) for high-temperature RWGS. The Pt@CeYLaScZrOx shows a RWGS CO production rate of 1350 mmol g-1 h-1 and a CO2 conversion rate of 55% as well as maintaining the initial CO production rate after 72 hours of RWGS operation under 600 °C, exhibiting unparalleled high-temperature stability. Various characterizations confirm the robustness of single atoms state of Pt in Pt@CeYLaScZrOx during high-temperature RWGS and theoretical calculation indicates that the high entropy property of CeYLaScZrOx leads to the thermodynamically stable state of Pt single atoms, thereby preventing the sintering of Pt. As a result, the Pt@CeYLaScZrOx could operate intense sunlight driven photothermal RWGS to show 45% of CO2 conversion rate and 100 hours of stable operation. This work provides a universal solution to prepare noble metal single-atom catalysts that stable under hydrogen rich and high-temperature environments.