Adsorption of Molecules on Defective CeO₂ for Advanced Catalysis

Abstract

Adsorption of molecules on active sites of heterogeneous catalysts significantly affects their catalytic performance, which provides a perspective to understand the catalytic process/mechanism at the atomic level and to establish structure–function relationships. This Perspective illustrates a strong correlation between the adsorption of reactants on CeO2-based catalysts and their improved catalytic activity and/or selectivity for various transformations. Regulating the oxygen defect of CeO2 provides an effective approach to construct two typical active sites of a frustrated Lewis pair (FLP) and dual-active site. Benefiting from the unique spatial and electronic structures, the FLP sites exhibit an “embedded” adsorption configuration of small molecules, promoting their effective activation and transformation. The dual-active sites constructed by metal clusters and oxygen vacancy of CeO2 could break the competitive adsorption of various molecules and thereafter enable highly active and selective hydrogenations. Finally, the possibilities and challenges in the adsorption behaviors of various molecules on CeO2-based catalysts are outlined. The tailorability of adsorption strength and selective configuration of molecules on active sites are anticipated to stimulate and guide the design of high-performing catalysts.

Advanced Biological Applications of Cerium Oxide Nanozymes in Disease Related to Oxidative Damage

“…The catalytic activity of cerium oxide is due to the transition between Ce 4+ and Ce 3+ ions. Ce ions can significantly adjust their electronic configuration, which can adapt to a given chemical environment. − The lattice structure of cerium oxide also exhibits O 2 vacancies (or defects), which can convert between CeO 2 and CeO 2– x . Cerium oxide nanoparticles play important roles in antioxidation based on switching from Ce 3+ to Ce 4+ , which mimics a variety of enzyme activities, such as those of superoxide dismutase (SOD) and catalase (CAT). − Various biological enzyme activities of cerium oxide have been discovered with roles in a number of biological fields, including biocatalysis, biomedicine, drug release, and biological scaffolds. − This review introduces biological enzyme activities of cerium oxide, including principles of activity, and discusses the latest progress in research in the field of biology (Figure ).…”

Customizing Wettability of Defect-Rich CeO2/TiO2 Nanotube Arrays for Humidity-Resistant, Ultrafast, and Sensitive Ammonia Response

“…In general, MOSs containing frustrated Lewis pairs (FLPs) usually act as active sites, owing to their ability to activate small molecules . In this regard, nanostructured ceria (CeO 2 ) with rich surface defects was found to contain abundant FLP sites with intrinsic affinity to small molecules with high reactivity …”

Regulation of frustrated Lewis pairs on CeO2 facilitates tandem transformation of styrene and CO2

“…3 The success of homogeneous FLPs has also spurred the development of heterogeneous ones that offer practical benefits such as easy separation and recycling, longer lifespan, and scalable productivity. [5][6][7][8] To date, constructing heterogeneous FLP catalysts is still challenging owing to the difficulty in breaking the commonly formed classic Lewis acid-base bonding. [9][10][11][12] By controlling structural oxygen defects, the physicochemical properties of reducible oxides can be modulated, allowing for the coexistence of independent surface Lewis acids and bases.…”

“…13,14 Inspired by these observations, FLP sites have been created on CeO 2 and In 2 O 3 surfaces to activate H 2 , CO 2 , H 2 O, etc. 7,15,16 However, the rigid solid lattice and lack of effective strategies to manipulate Lewis acid-base interaction have restricted the optimization of heterogeneous FLPs.…”

“…3 The success of homogeneous FLPs has also spurred the development of heterogeneous ones that offer practical benefits such as easy separation and recycling, longer lifespan, and scalable productivity. 5–8…”