In-situ constructed MoOx-TiO2 interfaces with abundant oxygen vacancies for noble metal-free and high-efficiency reverse water-gas shift reaction

Abstract

Interfacial modulation of transition metal oxide composites without noble metal is of great importance for CO₂ hydrogenation catalytic efficiency. Herein, we propose a heterogeneous interface engineering strategy to prepare the MoO_x-TiO₂ heterojunction catalyst with enhanced oxygen vacancy (O_V), which shows outstanding catalytic performance in the reverse water–gas shift (RWGS) reaction. MoO₃-TiO₂ heterojunction precursor is constructed by an in-situ solvent-thermal method. The electron transfer from TiO₂ to MoO₃ promotes the reduction of MoO₃, contributing to the formation of the MoO_x-TiO₂ heterojunction interface rich in O_V and then facilitating the adsorption and activation of CO₂. The catalyst shows excellent catalytic activity with a CO yield of 452.6 mmol g⁻¹ h⁻¹ at 400 °C. This performance is significantly improved over that of the MoO_x catalyst and superior to many reported Mo-based non-noble metal catalyst systems. In this study, the effective modulation of O_V of transition-metal oxides is realized by heterojunction engineering, which provides a new design paradigm for the development of high-efficiency CO₂ conversion catalysts.