Research Article Issue
Engineering oxygen vacancies and localized amorphous regions in CuO-ZnO separately boost catalytic reactivity and selectivity
Nano Research 2023, 16 (2): 2126-2132
Published: 07 October 2022
Abstract PDF (3.6 MB) Collect

Generating different types of defects in heterogeneous catalysts for synergetic promotion of the reactivity and selectivity in catalytic reactions is highly challenging due to the lack of effective theoretical guidance. Herein, we demonstrate a facile strategy to introduce two types of defects into the CuO-ZnO model catalyst, namely oxygen vacancies (OVs) induced by H2 partial reduction and localized amorphous regions (LARs) generated via the ball milling process. Using industrially important Rochow–Müller reaction as a representative, we found OVs predominantly improved the target product selectivity of dimethyldichlorosilane, while LARs significantly increased the conversion of reactant Si. The CuO-ZnO catalyst with optimized OVs and LARs contents achieved the best catalytic property. Theoretical calculation further revealed that LARs promote the generation of the Cu3Si active phase, and OVs impact the electronic structure of the Cu3Si active phase. This work provides a new understanding of the roles of different catalyst defects and a feasible way of engineering the catalyst structure for better catalytic performances.

Research Article Issue
Dual single-atom Ce-Ti/MnO2 catalyst enhances low-temperature NH3-SCR performance with high H2O and SO2 resistance
Nano Research 2023, 16 (1): 299-308
Published: 11 August 2022
Abstract PDF (7.6 MB) Collect

Mn-based catalysts have exhibited promising performance in low-temperature selective catalytic reduction of NOx with NH3 (NH3-SCR). However, challenges such as H2O- or SO2-induced poisoning to these catalysts still remain. Herein, we report an efficient strategy to prepare the dual single-atom Ce-Ti/MnO2 catalyst via ball-milling and calcination processes to address these issues. Ce-Ti/MnO2 showed better catalytic performance with a higher NO conversion and enhanced H2O- and SO2-resistance at a low-temperature window (100−150 °C) than the MnO2, single-atom Ce/MnO2, and Ti/MnO2 catalysts. The in situ infrared Fourier transform spectroscopy analysis confirmed there is no competitive adsorption between NOx and H2O over the Ce-Ti/MnO2 catalyst. The calculation results showed that the synergistic interaction of the neighboring Ce-Ti dual atoms as sacrificial sites weakens the ability of the active Mn sites for binding SO2 and H2O but enhances their binding to NH3. The insight obtained in this work deepens the understanding of catalysis for NH3-SCR. The synthesis strategy developed in this work is easily scaled up to commercialization and applicable to preparing other MnO2-based single-atom catalysts.

Total 2