International Joint Laboratory of Catalytic Chemistry, State Key Laboratory of Advanced Special Steel, Department of Chemistry, Research Center of Nano Science and Technology, College of Sciences, Shanghai University, 200444 Shanghai, China.
Environ Sci Technol. 2022 Apr 19;56(8):5170-5178. doi: 10.1021/acs.est.1c08715. Epub 2022 Apr 3.
Selective catalytic reduction (SCR) of NO over VO-based oxide catalysts has been widely used, but it is still a challenge to efficiently reduce NO at low temperatures under SO and HO co-existence. Herein, SO- and HO-tolerant catalytic reduction of NO at a low temperature has been originally demonstrated via engineering polymeric VO species by CeO. The polymeric VO species were tactfully engineered on Ce-VO composite active sites via the surface occupation effect of Ce, and the obtained catalysts exhibited remarkable low-temperature activity and strong SO and HO tolerance at 250 °C. The strong interaction between Ce and V species induced the electron transfer from V to Ce and tuned the SCR reaction via the E-R pathway between the NH/NH species and gaseous NO. In the presence of SO and HO, the polymeric VO species had not been hardly influenced, while the formation of sulfate species on Ce sites not only promoted the adsorption of NH species and the reaction between gaseous NO and NH but also facilitated the decomposition of ammonium bisulfate through weakening the strong bond between HSO and NH. This work provided a new strategy for SO- and HO-tolerant catalytic reduction of NO at a low temperature.
通过 CeO 工程化聚合 VO 物种，首次实现了 VO 基氧化物催化剂上选择性催化还原（SCR）NO 中同时存在 SO 和 HO 时的低温高效 NO 还原。Ce 的表面占位效应在 Ce-VO 复合活性位上巧妙地构建了聚合 VO 物种，所得到的催化剂在 250°C 时表现出显著的低温活性和对 SO 和 HO 的强耐受性。Ce 和 V 物种之间的强相互作用导致电子从 V 转移到 Ce，并通过 NH/NH 物种与气态 NO 之间的 E-R 途径来调变 SCR 反应。在存在 SO 和 HO 的情况下，聚合 VO 物种几乎没有受到影响，而 Ce 位上硫酸盐物种的形成不仅促进了 NH 物种的吸附以及气态 NO 和 NH 之间的反应，而且通过削弱 HSO 和 NH 之间的强键来促进了硫酸氢铵的分解。这项工作为低温下 SO 和 HO 耐受性的 NO 选择性催化还原提供了一种新策略。
