Atomically Dispersed Ni-Based Anti-Coking Catalysts for Methanol Dehydrogenation in a Fixed-Bed Reactor

Transition metal-based catalysts usually suffer from poor coke resistance during the dehydrogenation processes of hydrocarbon compounds in gas-solid heterogeneous systems, including methanol dehydrogenation. Herein, atomically dispersed Ni sites have been rationally anchored in nitrogen-doped carbon sheets (Ni-N4/NC), which could act as an integrated, active, and anticoking catalyst for methanol dehydrogenation with a high selectivity toward hydrogen and CO under 15 h-1 (weight hourly space velocities, WHSV) in a fixed-bed reactor. Both experimental and computational results reveal that the electronic structures of Ni-N4 sites promote the desorption of deep dehydrogenation product ethylene to release the Ni active centers, simultaneously giving a remarkably high H2 yield rate (1800 mol H2 mol-1 Ni h-1) and a high anticoking performance even under critical conditions.