Liu Lina, Dai Jing, Das Sonali, Wang Yaolin, Yu Han, Xi Shibo, Zhang Zhikun, Tu Xin
College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin 300350, China.
Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585, Singapore.
JACS Au. 2023 Feb 17;3(3):785-800. doi: 10.1021/jacsau.2c00603. eCollection 2023 Mar 27.
The removal of tar and CO in syngas from biomass gasification is crucial for the upgrading and utilization of syngas. CO reforming of tar (CRT) is a potential solution which simultaneously converts the undesirable tar and CO to syngas. In this study, a hybrid dielectric barrier discharge (DBD) plasma-catalytic system was developed for the CO reforming of toluene, a model tar compound, at a low temperature (∼200 °C) and ambient pressure. Periclase-phase (Mg, Al)O nanosheet-supported NiFe alloy catalysts with various Ni/Fe ratios were synthesized from ultrathin Ni-Fe-Mg-Al hydrotalcite precursors and employed in the plasma-catalytic CRT reaction. The result demonstrated that the plasma-catalytic system is promising in promoting the low-temperature CRT reaction by generating synergy between DBD plasma and the catalyst. Among the various catalysts, Ni4Fe1-R exhibited superior activity and stability because of its highest specific surface area, which not only provided sufficient active sites for the adsorption of reactants and intermediates but also enhanced the electric field in the plasma. Furthermore, the stronger lattice distortion of Ni4Fe1-R provided more isolated O for CO adsorption, and having the most intensive interaction between Ni and Fe in Ni4Fe1-R restrained the catalyst deactivation induced by the segregation of Fe from the alloy to form FeO . Finally, in situ Fourier transform infrared spectroscopy combined with comprehensive catalyst characterization was used to elucidate the reaction mechanism of the plasma-catalytic CRT reaction and gain new insights into the plasma-catalyst interfacial effect.
从生物质气化合成气中去除焦油和一氧化碳对于合成气的提质和利用至关重要。焦油的CO重整（CRT）是一种潜在的解决方案，它能同时将有害的焦油和CO转化为合成气。在本研究中，开发了一种混合介质阻挡放电（DBD）等离子体催化系统，用于在低温（约200°C）和常压下对模型焦油化合物甲苯进行CO重整。通过超薄Ni-Fe-Mg-Al水滑石前驱体合成了具有不同Ni/Fe比的方镁石相（Mg,Al）O纳米片负载的NiFe合金催化剂，并将其用于等离子体催化CRT反应。结果表明，该等离子体催化系统通过在DBD等离子体和催化剂之间产生协同作用，在促进低温CRT反应方面具有潜力。在各种催化剂中，Ni4Fe1-R表现出优异的活性和稳定性，因为其具有最高的比表面积，这不仅为反应物和中间体的吸附提供了足够的活性位点，还增强了等离子体中的电场。此外，Ni4Fe1-R更强的晶格畸变提供了更多孤立的O用于CO吸附，并且Ni4Fe1-R中Ni和Fe之间最强的相互作用抑制了由于Fe从合金中偏析形成FeO而导致的催化剂失活。最后，结合原位傅里叶变换红外光谱和全面的催化剂表征来阐明等离子体催化CRT反应的机理，并深入了解等离子体-催化剂界面效应。
