Efficient photothermal catalysis driving C–C coupling: challenges, strategies, and prospects for CO2 reduction to C2+ products

Abstract

Photothermal catalysis provides a unique pathway for driving CO₂ reduction to high-value multi-carbon (C₂₊) products by synergistically utilizing the “cold” electronic excitation of light energy and the “hot” activation effects of thermal energy. This review systematically analyzes the core challenges of this technology. At the intrinsic catalytic level, multidimensional bottlenecks exist: insufficient coverage of C₁ intermediates (*CO), the high energy barrier for C–C coupling, kinetic challenges in coordinating multi-step proton–electron transfer, and competition from the hydrogen evolution reaction (HER). At the materials and engineering level, optimization is urgently required for photothermal conversion efficiency, charge carrier separation, precise construction of active sites, and the coupling of light, heat, and mass transfer. Addressing these challenges, cutting-edge research has significantly enhanced C₂₊ selectivity through innovations in catalytic materials (plasmonic metal/narrow-bandgap semiconductor heterojunctions, defect engineering), reaction-pathway-guided design (tailoring sites for *CO dimerization and *CO–*CH_x coupling), and reactor optimization (microfluidic reactors enhancing mass transfer, membrane separation overcoming equilibrium limitations). The deep integration of theoretical simulations and in situ characterization is progressively revealing the microscopic dynamic mechanisms of C–C coupling under photothermal fields. Despite ongoing challenges in stability and cost for large-scale application, photothermal catalysis, leveraging its energy efficiency advantages and the high value of its products, has emerged as a promising high-tech direction for CO₂ resource utilization.