(340av) Engineering C1 Reaction Chemistry through Catalyst Design and Process Intensification

The conversion of single-carbon molecules such as CO, CO₂, CH₄, and CH₃OH (i.e., C₁ chemistry) plays a crucial role in the supply of energy and chemicals. My research interests focus on two aspects of C1 chemistry, methane upgrading processes and the hydrogenation of C₁ molecules and small hydrocarbon. The abundance of domestic natural gas reserves draws attention to the utilization of methane into higher-value chemicals. One of the promising routes is the non-oxidative dehydroaromatization of methane (MDA). The challenge of MDA lies in the methane activation step: high temperature is required to drive the reaction forward, leading to severe coke formation and rapid catalyst de-activation. Furthermore, MDA suffers from slow catalyst activation, which places a significant hurdle towards the commercialization of the MDA process. My research aims to tackle the two challenges of MDA through catalyst design and process intensification.

My first research area focuses on the intensification of the MDA reaction by microwave selective heating. We design H-(Fe)ZSM-5 as a microwave-sensitive catalyst and compare its MDA reaction performance in the microwave and conventional heating reactor. MW is found to selectively heat the metal site in H-(Fe)ZSM-5 catalyst. The temperature of the active site during microwave heating will be quantified using probe molecules. Furthermore, to scale up the MW-assisted catalytic processes, we conduct continuous zeolite synthesis to support a larger-scale microwave MDA reactor. Converting zeolite synthesis from batch to continuous mode can further intensify the reaction process to improve its efficiency and operation flexibility.

My second research area focuses on improving the H-(Fe)ZSM-5 catalyst activation period for MDA by designing of the catalyst and reaction process. To design a catalyst with a faster activation period, we studied the influence of Fe speciation on the catalyst activation time. Improvement on the activation period also requires understandings of the active phase formation process, which is investigated by in situ pretreatment experiments. CO pretreatment is found to reduce and carburize the iron oxide into iron carbide and significantly shortens the MDA activation time. Based on this finding, we propose an integrated CO₂ regeneration-reactivation process. By utilizing CO₂ for catalyst regeneration, i.e., removing coke via the Boudouard reaction, the catalyst can be simultaneously reactivated by the internally formed CO.

In my third research focus, we seek to intensify the hydrogenation of CO₂ and small hydrocarbons by applying the concept of chemical looping in a combined electrochemical and thermocatalytic study. WO₃ is identified as a promising H-carrier that can selectively store hydrogen in its lattice and donate hydrogen to the reactant of interest. Guided by computational predictions, we experimentally validate that selected metal oxides (WO₃, V₂O₅) can be modified to engage in desired chemistry, demonstrated through the partial hydrogenation of acetylene to ethylene.

Overall, our goal is to combine process intensification with catalyst design to improve the efficiency of C₁ chemistry reaction processes.