近日，广东工业大学环境健康与污染控制研究院、环境科学与工程学院安太成教授团队题为《Atomic Dispersed Pd site on Ti-SBA-15 for Efficient Catalytic Combustion of Typical Gaseous VOCs》的学术论文在Environ. Sci.: Nano 杂志上接受发表。论文的第一作者为温美成副教授，第二作者为博士研究生宋胜男，通讯作者为安太成教授。该研究工作主要是通过简单的溶剂弱还原法，制备低负载量且原子级分散的Pd负载Ti改性SBA-15分子筛催化剂，Pd的负载量仅为0.04 wt%，所制备催化剂在芳香类VOCs和烷烃/环烷烃类VOCs的催化燃烧时均展现出优异的催化活性和稳定性，通过吡啶红外光谱、VOCs程序升温脱附和密度泛函理论计算等方法，系统阐明了典型VOCs在Pd SSC/Ti-SBA-15表界面上降解的关键影响因素及其动力学反应机制。本研究对研发高效低成本催化剂及典型化工行业有机废气治理具有重要的指导意义。

论文DOI：https://doi.org/10.1039/D1EN00744K

制备原子级分散 Pd基催化剂是提高挥发性有机化合物(VOCs)的催化燃烧性能和降低Pd负载量的有效手段之一。在此，我们开发了一种简单易行的Pd负载方法，采用甲醇作为弱还原剂，将0.04 wt%的Pd负载于Ti掺杂的有序介孔二氧化硅（Pd SSC/Ti-SBA-15）载体上。AC-HAADF-STEM表征和原位CO漫反射红外光谱表征结果证明Pd以单原子的形式高度分散在Ti-SBA-15。同时，吡啶-漫反射红外光谱结果表明Ti掺杂有效提高了催化剂路易斯酸和布朗酸密度。所制备的Pd SSC/Ti-SBA-15对环己烷表现出优异的催化氧化活性(T₉₀ = 270^oC)，超过了Pd负载量为0.5 wt%的Pd_0.5 NPs/Ti-SBA-15 (T₉₀ = 370^oC)和没有Ti掺杂的Pd SSC/SBA-15 (T₉₀= 420^oC)。此外发现Pd SSC/Ti-SBA-15对环己烷、正己烷以及苯乙烯的催化燃烧表现出优异的催化活性和稳定性，在持续反应10小时后，仍对以上三种VOCs保持100%的矿化率。VOCs-TPD以及理论计算结果证明，Ti掺杂产生的大量酸性位点和原子级分散的Pd位点是促进性能提升的主要原因。该工作对开发低成本、高性能Pd基催化剂具有重要的指导意义。

Graphic Abstract：

论文英文摘要：

The development of atomic dispersed Pd site catalyst is attractive for maximizing metal utilization and reducing the dosage of Pd in the catalytic combustion of atmospheric volatile organic compounds (VOCs). Herein, we developed a scalable and economically feasible approach to prepare atomic dispersed palladium (Pd) site on titanium substituted order mesoporous silica (Pd SSC/Ti-SBA-15) with extremely low Pd loading (0.04 wt%). Characterizations of AC-HAADF-STEM and in-situ CO DRIFTS results revealed the existence of isolated Pd site in Pd SSC/Ti-SBA-15, and the Py-DRIFTS results demonstrated that the acidity of catalyst was improved by doping with a small amount of Ti. The as-prepared Pd SSC/Ti-SBA-15 exhibited excellent catalytic activity (T₉₀ = 270^oC) for cyclohexane combustion, exceeding that of Pd nanoparticles supported Ti-SBA-15 with high Pd loading amount (0.5 wt%) (T₉₀ = 370^oC) and Pd SSC/SBA-15 without Ti substitution (T₉₀= 420^oC). Furthermore, Pd SSC/Ti-SBA-15 displayed remarkable catalytic activity toward cyclohexane, n-hexane and styrene combustion and maintained 100% mineralization after 10 h. The excellent catalytic activity of the resultant Pd SSC/Ti-SBA-15 catalyst might be attributed to the considerable amount of acid sites derived from Ti substitution in promoting VOCs adsorption and the maximized Pd utilization realized by atomic Pd site supported on Ti-SBA-15. This work provides a new route for the development of low-cost and high-performance Pd-based catalysts for VOC abatement.

项目资助

该研究工作得到了国家自然科学基金（42077332）、广东省重点研发计划（2019B110206002）、广东省自然科学基金（2019A1515011469）、广东省本土创新团队（2017BT01Z032）和国家重点研发计划（2019YFC0214402）等项目支持。