亚纳米Pd/S-1催化剂催化乏风瓦斯燃烧性能研究

煤矿开采导致乏风瓦斯的大量排出，不仅对环境造成较大影响，而且与我国“双碳”理念相违背。本研究通过一锅水热法制备了一种封装在Silicalite-1分子筛载体中的亚纳米Pd团簇催化剂。通过XRD、BET、SEM、XPS和TEM对催化材料的物相组成、孔结构参数、微观形貌、元素化学态以及活性组分Pd的存在状态进行表征，探讨了活性组分负载量、空速和反应温度对催化性能的影响。研究结果表明：采用一锅水热法成功将Pd团簇封装在Silicalite-1分子筛载体孔道内，制备出高分散度的亚纳米Pd团簇催化剂；随着Pd负载量的增加，催化性能呈现先升高后降低的趋势，这是由于Pd原子间产生团聚效应，导致部分Pd原子被包覆，降低了活性组分与反应物间的接触面积；以Silicalite-1分子筛为载体，可以促进活性位点骨架氧向表面羟基转化，有助于甲烷催化氧化。对比现有甲烷催化氧化工艺，本研究制备的催化剂具有催化活性高、制备方法简单、处理成本低等优点。

Combustion performance of sub-nanometer Pd/S-1 catalyst for ventilation air methane

Coal mining leads to ventilation air methane emission, which not only pollutes the environment but also runs counter to "carbon neutral, carbon peaking" in China.This study prepared a sub-nanometer Pd cluster catalyst encapsulated in the Silicalite-1 molecular sieve support by the one-pot hydrothermal method, which has excellent catalytic activity and stability in methane catalytic oxidation reaction.The physical phase composition, pore structure parameters, microscopic morphology, chemical state and the present state of the active component Pd of the catalytic material were characterized by XRD, BET, SEM, XPS and TEM.This study then investigated the effects of active component loading, air velocity, reaction temperature and other conditions on the catalytic performance.The experimental results showed that the one-pot hydrothermal method successfully encapsulate Pd clusters within the pores of Silicalite-1 molecular sieve carriers to prepare highly dispersed sub-nanometer Pd cluster catalysts; the catalytic performance first increases and then decreases with the increase of Pd loading.This was due to the agglomeration effect between Pd atoms, resulting in the encapsulation of some Pd atoms and reducing the contact area between the active component and the reactants; in addition, using Silicalite-1 molecular sieve as a carrier can promote the conversion of active site skeletal oxygen to surface hydroxyl groups, which contributes to the catalytic oxidation of methane.The catalyst in this study excels existing methane catalytic process for its high catalytic activity, simple preparation, and low processing cost.