Surface defects on metal oxides have been proven to be crucial for anchoring the metal atoms, but the limited concentration of defects usually made it difficult to afford the high loading of atomically dispersed metals thus resulting in low apparent reaction rates in catalysis reactions. Herein, we report an effective, universal defect engineering strategy for creating rich surface defects as Pt anchoring sites on CeO2-based supports including commercial CeO2, CeO2-ZrO2 mixed oxide and CeO2-Al2O3 (CA). On these defect engineered supports, Pt catalysts with much higher Pt dispersion as prepared and superior CO oxidation activity as activated can be achieved comparing to the counterparts without defect engineering. Specifically, with loading of 1 wt.% Pt onto CA with and without defect engineering, 1.0Pt/CA-HD (CA-HD = CA support with ‘high density’ defects) showed only Pt single atoms (Pt1) substituting the Ce sites in CeO2 whereas the 1.0Pt/CA counterpart demonstrated both Pt1 and Pt clusters (PtC) (Figure 1C). Upon reduction activation, the embedded PtC sites with Pt atoms substituting Ce cations in CeO2 were present on 1.0Pt/CA-HD-a, while adsorbed PtC were observed on 1.0Pt/CA-a, respectively. The embedded PtC sites showed much higher activity in CO oxidation reaction, far exceeding the Pt1 sites and surface adsorbed PtC sites (Figure 1A). In addition, the 1.0Pt/CA-HD-a catalyst with unique embedded PtC sites and less CeO2 usage consistently showed higher CO oxidation activity and catalytic stability than conventional 1.0Pt/CeO2-a, suggesting its great potential in practical application (Figure 1B).

Pt catalyst on CeO2-based supports with engineered defects for enhanced CO oxidation

Where thousands of chemistry professionals meet to share ideas and advance scientific and technical knowledge. Spring 2023 abstracts, posters, and presentations will launch at the end of March.

ACS Spring 2023

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.