Recent advancements in CeO2-enabled liquid acid/base catalysis

Abstract

Acid/base catalysis plays a pivotal role in the synthesis of versatile chemicals, in which acidic/basic molecules are widely employed as highly effective catalysts. However, challenges associated with the recyclability of these homogeneous catalysts and the complexity of purification procedures impose limitations on their practical applications. Heterogeneous solid catalysts are emerging as viable alternatives to traditional acid/base catalysts. Among these, ceria (CeO₂), with the coexistence of surface acidic and basic sites, has demonstrated significant potential for acid/base catalysis. Herein, the present review provides a comprehensive overview of fundamental acid/base reactions catalyzed by CeO₂, including the dehydration and hydrolysis processes, the transformation of CO₂ to dimethyl carbonate (DMC), the hydrogenation of unsaturated groups, etc. In particular, the reaction mechanism is discussed in conjunction with an analysis of the acidic/basic sites on CeO₂. Additionally, various strategies to modulate the acid/base properties are outlined on CeO₂-based catalysts, with which the enhanced catalytic activity and selectivity are realized.