International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China.
Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
Environ Sci Technol. 2022 Aug 16;56(16):11646-11656. doi: 10.1021/acs.est.2c01812. Epub 2022 Jul 25.
SO-resistant selective catalytic reduction (SCR) of NO remains a grand challenge for eliminating NO generated from stationary combustion processes. Herein, SO-resistant NO reduction has been boosted by modulating electronic interaction of short-range Fe-O coordination over FeO/TiO catalysts. We report a remarkable SO-tolerant FeO/TiO catalyst using sulfur-doped TiO as the support. Via an array of spectroscopic and microscopic characterizations and DFT theoretical calculations, the active form of the dopant is demonstrated as SO residing at subsurface TiO locations. Sulfur doping exerts strong electronic perturbation to TiO, causing a net charge transfer from FeO to TiO via increased short-range Fe-O coordination. This electronic effect simultaneously weakens charge transfer from FeO to SO and enhances that from NO/NH to FeO, resulting in a remarkable "killing two birds with one stone" scenario, that is, improving NO/NH adsorption that benefits SCR reaction and inhibiting SO poisoning that benefits catalyst long-term stability.
用于固定燃烧过程中 NO 消除的抗 SO2 选择性催化还原（SCR）仍然是一项重大挑战。在此，通过调节 FeO/TiO 催化剂中短程 Fe-O 配位的电子相互作用，促进了抗 SO2 的 NO 还原。我们报告了一种使用硫掺杂 TiO2 作为载体的耐 SO2 的 FeO/TiO 催化剂。通过一系列光谱和微观特征以及 DFT 理论计算，证明了掺杂剂的活性形式为 SO2 位于 TiO2 的次表面位置。硫掺杂对 TiO2 产生强烈的电子扰动，通过增加短程 Fe-O 配位，导致从 FeO 到 TiO2 的净电荷转移。这种电子效应同时削弱了 FeO 到 SO2 的电荷转移，并增强了 NO/NH 到 FeO 的电荷转移，从而产生了显著的“一石二鸟”的效果，即改善了 SCR 反应中有利于的 NO/NH 吸附和抑制了有利于催化剂长期稳定性的 SO2 中毒。
