International Joint Laboratory of Catalytic Chemistry, State Key Laboratory of Advanced Special Steel, Department of Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China.
Langmuir. 2023 May 30;39(21):7434-7443. doi: 10.1021/acs.langmuir.3c00663. Epub 2023 May 18.
Mn-based catalysts are promising for selective catalytic reduction (SCR) of NO with NH at low temperatures due to their excellent redox capacity. However, the N selectivity of Mn-based catalysts is an urgent problem for practical application owing to excessive oxidizability. To solve this issue, we report a Mn-based catalyst using amorphous ZrTiO as the support (Mn/ZrTi-A) with both excellent low-temperature NO conversion and N selectivity. It is found that the amorphous structure of ZrTiO modulates the metal-support interaction for anchoring the highly dispersed active MnO species and constructs a uniquely bridged Mn bonded with the support through oxygen linked to Ti and Zr, respectively, which regulates the optimal oxidizability of the MnO species. As a result, Mn/ZrTi-A is not conducive to the formation of ammonium nitrate that readily decomposes to NO, thus further increasing N selectivity. This work investigates the role of an amorphous support in promoting the N selectivity of a manganese-based catalyst and sheds light on the design of efficient low-temperature deNO catalysts.
基于锰的催化剂由于其优异的氧化还原能力，在低温下用 NH 选择性催化还原（SCR）NO 方面很有前景。然而，由于过度的氧化性，基于锰的催化剂的 N 选择性是实际应用中亟待解决的问题。为了解决这个问题，我们报告了一种使用非晶 ZrTiO 作为载体的基于锰的催化剂（Mn/ZrTi-A），该催化剂具有优异的低温 NO 转化和 N 选择性。研究发现，ZrTiO 的非晶结构调节了金属-载体相互作用，从而固定了高度分散的活性 MnO 物种，并通过氧分别与 Ti 和 Zr 相连，构建了独特的桥接 Mn 与载体相连，这调节了 MnO 物种的最佳氧化能力。因此，Mn/ZrTi-A 不利于易于分解为 NO 的硝酸铵的形成，从而进一步提高 N 选择性。这项工作研究了非晶载体在提高锰基催化剂的 N 选择性方面的作用，为设计高效的低温脱硝催化剂提供了思路。
