Advances in triple-phase catalysis for energy and environmental applications.

Increasing attention on sustainable energy and the environment, particularly in areas like the greenhouse effect, green remediation, and green energy, has led to substantial research into the turnover of gas-phase molecules such as carbon dioxide, oxygen, and hydrogen. For gas-involved heterogeneous reactions, a "gas-liquid-solid" triple-phase catalysis system is essential to facilitate industrial-scale production and maintain continuous flow flexibility. In this system, the solid phase functions as either a catalyst or an electron conductor, while the liquid phase serves as a storage medium for products from gas molecule reactions or as an ionic conductor for charge balance. However, achieving a stable triple-phase interface remains challenging, posing obstacles to long-term operational performance and widespread industrial adoption. In this review, we outline the evolutionary path, fundamental principles, recent optimization strategies, and advanced in situ characterization in triple-phase catalysis research. We also explore typical environmental applications of triple-phase catalysis, such as air treatment, waste management, hydrogen evolution, CO2 reduction, and oxygen reduction, focusing on their mechanisms, architecture optimization, and influential factors. Finally, we discuss future directions in triple-phase catalysis to deepen process understanding, enhance performance, and reduce costs. This review aims to inspire and guide future research in triple-phase catalysis for more sustainable energy and environmental applications.