Plasma-Catalytic CO2 Reforming of Toluene over Hydrotalcite-Derived NiFe/(Mg, Al)O x Catalysts

Lina Liu; Jing Dai; Sonali Das; Yaolin Wang; Han Yu; Shibo Xi; Zhikun Zhang; Xin Tu

doi:10.1021/jacsau.2c00603

Plasma-Catalytic CO₂ Reforming of Toluene over Hydrotalcite-Derived NiFe/(Mg, Al)O _x Catalysts

JACS Au. 2023 Feb 17;3(3):785-800. doi: 10.1021/jacsau.2c00603. eCollection 2023 Mar 27.

Authors

Lina Liu¹, Jing Dai¹, Sonali Das², Yaolin Wang³, Han Yu¹, Shibo Xi⁴, Zhikun Zhang⁵, Xin Tu³

Affiliations

¹ College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin 300350, China.
² Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585, Singapore.
³ Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ, U.K.
⁴ Institute of Chemical and Engineering Sciences, A STAR, 1 Pesek Road, Jurong Island, Singapore 627833, Singapore.
⁵ School of Energy and Environmental Engineering, Tianjin Key Laboratory of Clean Energy and Pollution Control, Hebei University of Technology, Tianjin 300401, China.

Abstract

The removal of tar and CO₂ in syngas from biomass gasification is crucial for the upgrading and utilization of syngas. CO₂ reforming of tar (CRT) is a potential solution which simultaneously converts the undesirable tar and CO₂ to syngas. In this study, a hybrid dielectric barrier discharge (DBD) plasma-catalytic system was developed for the CO₂ reforming of toluene, a model tar compound, at a low temperature (∼200 °C) and ambient pressure. Periclase-phase (Mg, Al)O _x 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^2- for CO₂ 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 _x . 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.