A series of Cu–Mn–SSZ-13 catalysts were obtained by co-exchange of Mn and Cu into SSZ-13 together (ion exchange under a mixed solution of Cu(NO₃)₂ and Mn(NO₃)₂) and compared with Cu–SSZ-13 catalysts on the selective catalytic reduction (SCR) of nitric oxide (NO) by ammonia. The effects of total ion exchange degree and the effect of Mn species on the structure and performance of catalysts before and after hydrothermal aging were studied. All fresh and aged catalysts were characterized with several methods including temperature-programmed desorption with NH₃ (NH₃-TPD), X-ray diffraction (XRD), ²⁷Al and ²⁹Si solid-state nuclear magnetic resonance (NMR), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and low-temperature N₂ adsorption–desorption techniques. The results showed that the increase of the total ion exchange degree can reduce the content of residual Brønsted acid sites of catalysts, thus relieved the dealumination and the decrease of crystallinity of the catalyst during hydrothermal aging. The moderate addition of a Mn component in Cu–Mn–SSZ-13 catalysts significantly increased the activity of NO conversion at low temperature range. The selected Cu(0.2)Mn(0.1)–SSZ-13 catalyst achieved a high NO conversion of >90% in the wide and low temperature range of 175–525 °C and also exhibited good N₂ selectivity and excellent hydrothermal stability, which was related to the inhibition of the Mn component on the aggregation of Cu species and the pore destruction of the catalyst during hydrothermal aging.

The electrochemical reduction of CO₂ is a promising strategy to achieve efficient conversion and utilization. In this paper, a series of Zn catalysts were prepared by electrodeposition in different atmospheric conditions (N₂, CO₂, H₂, CO). A fibrous Zn catalyst (Zn-CO₂) exhibits high electrochemical activity and stability. The Zn-CO₂ catalyst shows 73.0% faradaic efficiency of CO at −1.2 V vs. RHE and the selectivity of CO almost did not change over 6 h in −1.2 V vs. RHE. The excellent selectivity and stability is attributed to the novel fibrous morphology, which increases the electrochemical active surface area. X-ray diffraction (XRD) results show that Zn-CO₂ catalyst has a higher proportion of Zn (101) crystal planes, which is considered to be conducive to the production of CO. The search further demonstrates the importance of morphology control for the preparation of highly active and stable catalysts.