Multidimensional Regulation of Interfacial Microenvironment by Alkali Metal Ions for Selective Photothermal CO2 Conversion

Abstract

Photothermal CO 2 conversion holds great promise for sustainable fuel synthesis, yet steering selectivity toward valuable multi-carbon products remains a fundamental challenge, limited by the intricate coupling of electronic, energetic, and kinetic factors at catalyst interfaces. This review highlights alkali metal ions (Li + , Na + , K + , Cs + ) as dynamic "electronic microenvironment regulators" that break the conventional activity-selectivity trade-off by promoting interfacial electron accumulation. We propose a unifying "electronic-energy-process" three-dimensional framework to decipher their cross-scale functions: (i) electronically, by tuning active-site electron density and intermediate adsorption; (ii) energetically, by building localized electric fields to enhance carrier separation; and (iii) procedurally, by driving photothermal interfacial reconstruction to steer reaction pathways. This framework systematically rationalizes alkali-metal effects across carbon-based, metallic, semiconductor, and insulator, integrating scattered mechanistic insights into a coherent design paradigm.We further outline key challenges-including dynamic interfacial evolution, alkali leaching, and scalable reactor integration-and discuss forward-looking strategies combining in-situ characterization, machine-learning-aided catalyst design, and multi-field coupled systems. By providing a multidimensional perspective from atomic-scale regulation to macroscopic process optimization, this review aims to accelerate the development of highly selective, stable, and efficient photothermal CO 2 conversion technologies for a carbon-neutral future.