Tuning of active nickel species in MOF-derived nickel catalysts for the control on acetic acid steam reforming and hydrogen production

Abstract

Acetic acid (AcOH) steam reforming for hydrogen (H2) generation was investigated using a zero valent nickel complex (Ni-comp) derived from a metal-organic framework precursor supported over aluminum oxide/lanthanum oxide-cerium dioxide (ALC). The effects of Ni loading ratio (10, 15, and 20 wt%) on the catacatalytic activity were investigated in the range of 400 to 650 °C to H2 generation. The Ni-comp/ALC catalysts exhibited almost complete conversion of AcOH (XAcOH >98%) to H2 (XH2>90%) alongside some impurities (e.g., carbon monoxide, methane, and carbon dioxide). A maximum H2 yield (91.36% (0.064 mol-1 gcat−1 h−1)) was attained at the following conditions: 15 wt% Ni loading, steam to carbon molar ratio of 6.5, weight hourly space velocity of 1.05 h−1, and 600 °C. The 15 wt% Ni catalyst maintained sufficient stability over 40 h reaction time. Accordingly, Ni-comp-ALC interactions were seen to efficiently improve the activity and stability of the catalyst so as to synergistically resist coke deposition and metal sintering through the formation of a large number of free Ni particles and oxygen vacancies.