Reciprocal regulation between support defects and strong metal-support interactions for highly efficient reverse water gas shift reaction over Pt/TiO2 nanosheets catalysts

Abstract

Strong metal-support interaction (SMSI) is regarded as one of the most important concepts in heterogeneous catalysis; however, few researches are focused on SMSI regulating the support structure, properties and their roles on the catalytic performance. Herein, anatase TiO2{001} nanosheets pretreated in different atmosphere were used to load Pt for reverse water gas shift reaction. The Pt/N-doped TiO2 catalysts exhibited significantly superior catalytic performance. The investigation demonstrated that defects and doped-N enhance the Pt dispersion while Pt and SMSI in turn promote defects regeneration during activation in H2. During reaction, surface defects enable CO2 activation to generate active intermediates which easily decompose into CO. Furthermore, the small Pt particles and SMSI facilitate H2 dissociative adsorption and spillover to replenish both surface defects and bulk Ti3+. Besides, a novel reaction route has been observed that the stable bulk Ti3+ in N-doped TiO2 migrate and transform to surface defects, enhancing catalytic performance.