Single atoms of platinum group metals on CeO represent a potential approach to lower precious metal requirements for automobile exhaust treatment catalysts. Here we show the dynamic evolution of two types of single-atom Pt (Pt) on CeO, i.e., adsorbed Pt in Pt/CeO and square planar Pt in PtCeO, fabricated at 500 °C and by atom-trapping method at 800 °C, respectively. Adsorbed Pt in Pt/CeO is mobile with the in situ formation of few-atom Pt clusters during CO oxidation, contributing to high reactivity with near-zero reaction order in CO. In contrast, square planar Pt in PtCeO is strongly anchored to the support during CO oxidation leading to relatively low reactivity with a positive reaction order in CO. Reduction of both Pt/CeO and PtCeO in CO transforms Pt to Pt nanoparticles. However, both catalysts retain the memory of their initial Pt state after reoxidative treatments, which illustrates the importance of the initial single-atom structure in practical applications.
Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, School of Materials Science and Engineering & National Institute for Advanced Materials, Nankai University, Tianjin 300350, P. R. China.
Nanozyme catalytic therapeutic efficacy is limited by the finite enzyme activity and specificity. In this work, nitrogen-doped carbon loaded with a cerium single-atom nanozyme (Ce SAs@NC) is synthesized, exhibiting tumor specificity and excellent multiple enzyme-like activities. Compared with nitrogen-doped carbon loaded with CeO nanoparticles, Ce SAs@NC shows excellent peroxidase-like and catalase-like activity.
* Researchers propose that changing the coordination symmetry of these SACs can enhance their electronic properties, which helps in better adsorbing and activating reactant molecules.
* Using a ceria-based Ru-SAC (Ru-CeO) as a case study, they demonstrate that an asymmetric configuration (P-Ru-CeO) significantly improves photocatalytic performance through enhanced electron delocalization, offering a novel approach to designing more efficient catalysts.
Department of Applied Chemistry for Environment, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, 1-1 Minami-osawa, Hachioji, Tokyo, 192-0397, Japan.
Au single atoms and clusters were stabilized on Mg-Al layered double hydroxide nanoparticles (LDH NPs), and the obtained Au@LDH NPs were supported on SiO and CeO. After hydrogen reduction, Au single atoms were found together with Au clusters on LDH/SiO. In contrast to Au single-atom catalysts which are deposited in metal vacancies of oxide supports, the LDH NPs stabilize very small Au species despite the absence of metal vacancies.
International Joint Laboratory of Catalytic Chemistry, State Key Laboratory of Advanced Special Steel, Innovation Institute of Carbon Neutrality, Department of Chemistry, College of Sciences, Shanghai University, Shanghai, 200444, People's Republic of China.
Optimizing the reactivity and selectivity of single-atom catalysts (SACs) remains a crucial yet challenging issue in heterogeneous catalysis. This study demonstrates selective catalysis facilitated by a polyoxometalates-mediated electronic interaction (PMEI) in a Pt single-atom catalyst supported on CeO modified with Keggin-type phosphotungstate acid (HPW), labeled as Pt/CeO-HPW. The PMEI effect originates from the unique arrangement of isolated Pt atoms and HPW clusters on the CeO support.
Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China.
Synergistic catalytic removal of multipollutants (e.g., volatile organic compound (VOC) oxidation and nitrogen oxide (NO) reduction) is highly demanded due to the increasingly strict emission standards.
