Synergism of Ultrasmall Pt Clusters and Basic La_2O_2CO_3 Supports Boosts the Reverse Water Gas Reaction Efficiency

摘要

The reverse water-gas shift reaction (RWGS) has been regarded as a promisingapproach for fighting climate change caused by the excessive emission of thegreenhouse gas CO_2, but it still suffers from relatively poor low-temperaturereactivity. Herein, a high-performance RWGS catalyst composed of ultrasmallPt clusters (1.38 nm on average) anchored by La_2O_2CO_3 support (PtNC/LOC),which possesses a record CO production rate of 2678 molCO mol_(Pt)~(?1) h~(?1) withnearly 100 CO selectivity at 300 ℃, is reported. The specific activity isnearly 1.5 and 7.9 fold higher than that of Pt single atoms and nanoparticleson La_2O_2CO_3, respectively. More importantly, over 87.7 of the initial activityof PtNC/LOC remains after 80 h constant operation at 380 ℃, firmly verifyingthe structural robustness. LOC support is essential, because of not only themoderate basicity that can boost the reaction efficiency but also the stronginteraction with Pt species that can stabilize the ultrasmall particle size. Furtherinvestigations also point out the key role of the Pt clusters. The two keysteps, CO_2 adsorption, and CO desorption, individually prefer electron-richand electron-deficient Pt species. Ultrasmall Pt clusters successfully integratethe unique surface states of single atoms and nanoparticles, thus achievingexcellent low-temperature RWGS performance.