Mao Yanghui, Wang Xiaofeng, Miao Birong, Liu Yuyang, Li Ke, Li Qingbo, Jia Hongliang, Su Wanting
Joint R&D Center for Sustainable Marine Fuels, College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
Joint R&D Center for Sustainable Marine Fuels, College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
J Colloid Interface Sci. 2025 Oct;695:137798. doi: 10.1016/j.jcis.2025.137798. Epub 2025 May 5.
Selective catalytic reduction of NO with CH (CH-SCR) is a promising strategy for NO abatement that utilizes CH escaping from the incomplete combustion of liquefied natural gas (LNG) to reduce NO. However, developing CH-SCR catalysts with high efficiency at temperature < 450°C remains a significant challenge. Herein, this work reported an In/H-SSZ-39-Hy zeolite catalyst (Hy represents hybrid AEI/MOR topology) with superior activity by utilizing the synergistic effect of InO and Brønsted acid (BA). The maximum NO conversion (74 %) achieved over the In/H-SSZ-39-Hy at 430°C with a gas hourly space velocity (GHSV) of 48,000 h, which was significantly higher than that over the commercial In/H-SSZ-39 and In/H-SSZ-13 catalysts. A series of characterizations revealed that abundant BA sites and surface adsorbed oxygen contributed to the formation of reactive InO and nitrate species, which played a critical role in facilitating CH activation and redox cycling. In situ DRIFTS confirmed that CH was activated at the InO site and reacted with nitrate at the BA sites to form the important intermediate CHNO, which further converted to N, CO and HO. This study elucidates the synergistic roles of InO and BA in CH-SCR, and provides a deeper understanding of catalytic mechanism.
用 CH 选择性催化还原 NO（CH-SCR）是一种很有前景的 NO 减排策略，它利用液化天然气（LNG）不完全燃烧逸出的 CH 来还原 NO。然而，开发在温度低于 450°C 时具有高效性的 CH-SCR 催化剂仍然是一项重大挑战。在此，本工作报道了一种通过利用 InO 和布朗斯特酸（BA）的协同效应而具有优异活性的 In/H-SSZ-39-Hy 沸石催化剂（Hy 代表 AEI/MOR 混合拓扑结构）。在 430°C、气体时空速度（GHSV）为 48000 h⁻¹ 的条件下，In/H-SSZ-39-Hy 上实现的最大 NO 转化率为 74%，这显著高于商业 In/H-SSZ-39 和 In/H-SSZ-13 催化剂。一系列表征表明，丰富的 BA 位点和表面吸附氧有助于活性 InO 和硝酸盐物种的形成，它们在促进 CH 活化和氧化还原循环中起关键作用。原位漫反射红外傅里叶变换光谱（DRIFTS）证实，CH 在 InO 位点被活化，并在 BA 位点与硝酸盐反应形成重要中间体 CH₃NO，其进一步转化为 N₂、CO₂ 和 H₂O。本研究阐明了 InO 和 BA 在 CH-SCR 中的协同作用，并对催化机理有了更深入的理解。
