Gao Ruyi, Zhang Manchen, Liu Yuxi, Xie Shaohua, Deng Jiguang, Ke Xiaoxing, Jing Lin, Hou Zhiquan, Zhang Xing, Liu Fudong, Dai Hongxing
Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Department of Environmental Chemical Engineering, Beijing University of Technology, Beijing 100124, China.
Beijing Key Laboratory of Microstructure and Properties of Solids, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China.
Environ Sci Technol. 2022 Jul 5;56(13):9672-9682. doi: 10.1021/acs.est.2c00437. Epub 2022 Jun 21.
Pt-based catalysts can be poisoned by the chlorine formed during the oxidation of multicomponent volatile organic compounds (VOCs) containing chlorinated VOCs. Improving the low-temperature chlorine resistance of catalysts is important for industrial applications, although it is yet challenging. We hereby demonstrate the essential catalytic roles of a bifunctional catalyst with an atomic-scale metal/oxide interface constructed by an intermetallic compound nanocrystal. Introducing trichloroethylene (TCE) exhibits a less negative effect on the catalytic activity of the bimetallic catalyst for -xylene oxidation, and the partial deactivation caused by TCE addition is reversible, suggesting that the bimetallic, HCl-etched PtSn(E)/CeO catalyst possesses much stronger chlorine resistance than the conventional Pt/CeO catalyst. On the site-isolated Pt-Sn catalyst, the presence of aromatic hydrocarbon significantly inhibits the adsorption strength of TCE, resulting in excellent catalytic stability in the oxidation of the VOC mixture. Furthermore, the large amount of surface-adsorbed oxygen species generated on the electronegative Pt is highly effective for low-temperature C-Cl bond dissociation. The adjacent promoter (Sn-O) possesses the functionality of acid sites to provide sufficient protons for HCl formation over the bifunctional catalyst, which is considered critical to maintaining the reactivity of Pt by removing Cl and decreasing the polychlorinated byproducts.
基于铂的催化剂可能会被含氯挥发性有机化合物（VOCs）氧化过程中形成的氯所毒化。提高催化剂的低温抗氯性对工业应用很重要，尽管这仍然具有挑战性。我们在此展示了一种由金属间化合物纳米晶构建的具有原子尺度金属/氧化物界面的双功能催化剂的关键催化作用。引入三氯乙烯（TCE）对双金属催化剂催化二甲苯氧化的活性影响较小，并且TCE添加导致的部分失活是可逆的，这表明双金属HCl蚀刻的PtSn(E)/CeO催化剂比传统的Pt/CeO催化剂具有更强的抗氯性。在位点隔离的Pt-Sn催化剂上，芳烃的存在显著抑制了TCE的吸附强度，从而在VOC混合物氧化中具有出色的催化稳定性。此外，在带负电的Pt上产生的大量表面吸附氧物种对低温C-Cl键解离非常有效。相邻的促进剂（Sn-O）具有酸性位点的功能，可为双功能催化剂上HCl的形成提供足够的质子，这被认为对于通过去除Cl和减少多氯副产物来维持Pt的反应性至关重要。
