LaCoO3 supported Pt for efficient photo-thermal catalytic reverse water-gas shift via the Mott-Schottky effect

Abstract

The conversion of CO2 into valuable chemicals like CO through the reverse water–gas shift (RWGS) process is a significant strategy for both mitigating and utilizing atmospheric CO2. It is crucial to enhance catalytic performance for RWGS at low-temperatures by designing efficient photo-thermal co-catalysts with strong photo-response and photo-thermal effects. Herein, Pt nanoparticles (NPs) supported on LaCoO3 with Mott-Schottky heterojunctions were synthesized to improve the performance of RWGS at low-temperatures. The results show that the narrow bandgap of LaCoO3 has excellent light-absorbing properties, generating abundant photo-carriers under light irradiation. The presence of ultra-small Pt NPs effectively reduces carrier recombination, enhancing carrier separation efficiency. 1.0 Pt/LaCoO3 (1.0 wt% Pt loading) at 350 °C under photo-thermal conditions showed a CO2 conversion of 32.9 % and CO production rate of 58.6 mmol gcat−1 h−1. The excellent photo-thermal co-catalytic performance of Pt/LaCoO3 was attributed to the remarkable Mott-Schottky heterojunctions of Pt with high electron density and the narrow bandgap of the support with abundant surface defects. This study provides valuable insights into the development of Mott-Schottky heterojunction catalysts for efficient photo-thermal co-catalytic RWGS at low-temperatures.