Nowadays catalytic technologies are widely used to purify indoor and outdoor air from harmful compounds. Recently, Ag-CeO 2 composites have found various applications in catalysis due to distinctive physical-chemical properties and relatively low costs as compared to those based on other noble metals. Currently, metal-support interaction is considered the key factor that determines high catalytic performance of silver-ceria composites. Despite thorough investigations, several questions remain debating. Among such issues, there are (1) morphology and size effects of both Ag and CeO 2 particles, including their defective structure, (2) chemical and charge state of silver, (3) charge transfer between silver and ceria, (4) role of oxygen vacancies, (5) reducibility of support and the catalyst on the basis thereof. In this review, we consider recent advances and trends on the role of silver-ceria interactions in catalytic performance of Ag/CeO 2 composites in low-temperature CO oxidation, soot oxidation, and volatile organic compounds (VOCs) abatement. Promising photoand electrocatalytic applications of Ag/CeO 2 composites are also discussed.Au [17][18][19][20][21][22][23], Ru [24,25], Rh [26][27][28][29], and Cu [30,31] were proposed. Metal oxide-based catalysts (Co 3 O 4 [32], MnO x [33], etc.) also attracted wide interest. However, a significant part of the developed catalysts has limited use under real conditions due to high costs of noble metals (the loading of palladium, platinum, gold is of 2-10 wt. %), relatively low stability to "hard" conditions of oxidation processes causing the loss of active component and reduction of the catalyst activity and selectivity. Therefore, the development of high-performance affordable and stable catalysts for low-temperature total oxidation of harmful compounds is still challenging. Efficiency and costs of such catalysts are connected with proper selection of the type of active component, support, and preparation method [34].Recently, supported silver catalysts have brought about wide interest due to their high activity in low-temperature oxidation processes. Different supports are studied (SiO 2 , CeO 2 , MnO x , TiO 2 , Al 2 O 3 , ZrO 2 , etc.) [35][36][37][38]. It is shown that an enhanced catalytic activity of Ag-based catalysts can be achieved by using reducible metal oxides as supports and by controlling the metal-support interaction to provide synergistic effect between active sites of the support and noble metal [39].Among the supports mentioned, CeO 2 brings about high interest, since it combines exceptional redox and acid-base properties with oxygen storage, which can be controlled by proper preparation methods and treatments. Moreover, these distinctive properties of ceria cause its wide applications as a support for catalysts. For this reason, highly active and relatively inexpensive Ag/CeO 2 composite is considered promising heterogeneous catalyst for total oxidation of harmful organic compounds, including formaldehyde [40], , soot [44][45][46][47][48][49]. The Ag...

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Ag–CeO2 catalysts (20 mol % Ag) were synthesized using different techniques (co-precipitation, impregnation, and impregnation of pre-reduced ceria), characterized by XRD, N2 sorption, TEM, H2-TPR methods, and probed in room-temperature p-nitrophenol reduction into p-aminophenol in aqueous solution at atmospheric pressure. The catalyst preparation method was found to determine the textural characteristics, the oxidation state and distribution of silver and, hence, the catalytic activity in the p-nitrophenol reduction. The impregnation technique was the most favorable for the formation over the ceria surface of highly dispersed silver species that are active in the p-nitrophenol reduction (the first-order rate constant k = 0.656 min−1).

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