Solution Plasma Processing Single‐Atom Au₁ on CeO₂ Nanosheet for Low Temperature Photo‐Enhanced Mars–van Krevelen CO Oxidation

Abstract

Creating oxygen vacancies in metal oxide support holds promise in anchoring and stabilizing single atom metals, activating the lattice oxygen of metal oxide and accelerating Mars–van Krevelen (MvK) catalytic oxidation. However, it is challenging to achieve nearly 100% trapping of single atom metal in solution by oxygen vacancy typed metal oxide, resulting from the difficulty in synchronized formation of oxygen vacancies and capture of the single atom metal. In this study, a solution plasma process (SPP) is developed, enabling ≈99% trapping of single atom Au by using oxygen vacancy typed CeO2 nanosheet in 2 min. Owing to the large number of electrons and free radicals present in the plasma region, the SPP can simultaneously reduce HAuCl4 to single‐atom Au and bring oxygen vacancies as anchoring sites onto CeO2. The catalytic test of CO oxidation assisted by solar light can reach a conversion of 91.7% with a high turnover frequency of 1.3 s−1 at room temperature, far exceeding the requirements for the “150 °C challenge.” A photo‐enhanced MvK pathway is proposed for the superior performance of Au1/CeO2. This study not only explores a novel solution approach to prepare single‐atom metal catalysts, but also provides an effective strategy for efficient low‐temperature catalytic oxidation.

Constructing Heterointerfaces in Dual-Phase High-Entropy Oxides to Boost O2 Activation and SO2 Resistance for Mercury Removal in Flue Gas

“…To gain insights into the oxygen vacancies in the 4C and Co-HEO, EPR data were recorded. At g = 2.003, a symmetric peak appears (Figure B), which represents oxygen vacancies with unpaired electrons . Compared to 4C, Co-HEO has a higher peak intensity, suggesting more oxygen vacancies.…”

“…At g = 2.003, a symmetric peak appears (Figure 3B), which represents oxygen vacancies with unpaired electrons. 33 Compared to 4C, Co-HEO has a higher peak intensity, suggesting more oxygen vacancies. In line with the HRTEM results, these findings confirm the characteristic of "rich structural defects".…”

Precious metal catalyst recycling through photocatalytic dissolution

“…S13†). 36,37 To this end, we verified that Au was successfully re-deposited on the surface of CeO 2 using HRTEM and the corresponding energy dispersive X-ray spectroscopy (EDS) mapping, with Au sizes and exposed crystalline surfaces consistent with Au/CeO 2 -fresh (Fig. 3b and c).…”

Recent Progress on Density Functional Theory Calculations for Catalytic Control of Air Pollution

“…Saqlain et al also investigated the MvK mechanism of CO oxidation on Au 10 /TiO 2 on by means of DFT calculations . The same mechanism was also investigated in the study of Yang et al and Xing et al , According to studies from very early times, the scientific community believes that catalytic CO oxidation reactions are usually L-H mechanisms and E-R mechanisms are also involved in the CO oxidation reaction . Lou et al paved the way for loaded catalysts by pointing out that CO 2 is generated mainly through two reaction pathways over Au-loaded catalysts, following the L-H mechanism (mainly) and the MvK mechanism, respectively .…”