Asymmetric Interaction between Carbon and Ni-Cluster in Ni–C–In Photothermal Catalysts for Point-Concentrated Solar-Driven CO2 Reverse Water–Gas Shift Reaction

Abstract

A concentrated solar reaction device has been designed for the solar-driven photothermal CO₂ reverse water–gas shift reaction, in which solar-to-chemical conversion efficiency would be up to 26% via a concentrated solar panel. Meanwhile, a special photothermal Ni–C–In catalyst (Ni/C–In₂O₃) with interstitial C, the In₃Ni₂ intermetallic compound, and disordered Ni clusters has been synthesized. As a result, the SO₂-tolerant Ni/C–In₂O₃ catalyst exhibits an outstanding solar-driven photothermal catalytic performance (near thermodynamic limitation) with 100% CO selectivity and a 20.96 mmol g_cat^–1 h^–1 CO production rate for solar-driven CO₂ hydrogenation under concentrated solar irradiation (around 1521.9 mW/cm²) even sunlight without external heating. The incorporation of interstitial C and exposed Ni clusters in the Ni–C–In intermetallic catalyst could strengthen intensive solar light absorption. Moreover, quasi in situ XPS and DFT theoretical calculation results validate that asymmetric interaction between interstitial C and the Ni-cluster not only effectually regulates the electronic structure of the Ni–C–In intermetallic catalyst but also greatly optimizes the activation of H₂ and CO₂ molecules and the energy barriers of key reaction dynamics (HCOO* formation and dehydrogenation) in the RWGS reaction. Accordingly, this study provides a promising strategy for the electronic structure modification of photothermal functional catalysts with C modification to boost CO₂ hydrogenation, putting forward an important step toward practical solar-to-fuel production with concentrated natural sunlight.