Engineering Dual Active Sites at the Interface between Nanoporous Pt and Nanosized CeO₂ to Enhance Photo‐Thermocatalytic CO Oxidation

Abstract

Effective catalytic oxidation of toxic emissions at low temperatures has great significance on environmental protection. Herein, a novel structure of Pt/CeO2 catalyst, composed of abundant CeO2 clusters captured by nanoporous Pt particles, is designed to enhance the photo‐thermocatalytic CO oxidation by boosting the amount of active sites. The nanosized CeO2 support is fabricated by vacuum thermal decomposition and then the Pt/CeO2 catalyst with a nanoporous structure is synthesized by a one‐pot solution reduction method in a mild condition. The synthesized catalyst exhibits great low‐temperature CO catalytic oxidation activity, and the temperature for 90% CO conversion is 154 °C, achieving comparable catalytic activity with the single‐atom Pt/CeO2 catalyst. Abundant dual active sites, in terms of active oxygen absorbed on the oxygen vacancies and spillover from ceria to Pt, and active Pt sites located near the perimeter of the Pt–CeO2 interface, are formed to improve the photo‐thermocatalytic activity for CO oxidation.

The catalytic activity of the Pr2Zr2−xFexO7±δ system for the CO oxidation reaction

“…CeO 2 is capable of storing oxygen under combustion conditions and can release oxygen when exposed to reducing agents. [20][21][22][23][24] Thus, the oxygen vacancies are an essential point to achieve high catalytic performance in oxidation reactions. Depending on the reaction conditions, pure CeO 2 can fully convert CO into CO 2 in the temperature range between 250 and 400 • C. [25][26][27][28] Other materials used as catalysts for this reaction are shown in Table S1.…”

“…The conversion between the two oxidation states is the key process that determines the ability of cerium oxide to release or adsorb oxygen. CeO 2 is capable of storing oxygen under combustion conditions and can release oxygen when exposed to reducing agents 20–24 . Thus, the oxygen vacancies are an essential point to achieve high catalytic performance in oxidation reactions.…”

Ag–O–Ce3+ atomic interface and surface oxygen vacancies on CeO2 synergistically promoted the selective visible photocatalytic reduction of carbon dioxide

“…The improvement of the separation efficiency and fast migration of the charge carriers to the photocatalyst surface are the most effective strategies to improve the photocatalytic activity. 12,13 Recently, in order to change the chemical instability of the V O s of CeO 2 , there have been increasingly more reports about the introduction of different components to stabilize the V O s of CeO 2 , such as the loading of Cu, 14,15 Pt, 16 Ag, 17 and other metals. There are also different forms of composite with Fe 2 O 3 , 18 TiO 2 , 19,20 and others, which can change the coordination number of Ce 4+ and transform Ce 4+ to Ce 3+ , forming more defect sites.…”