Low-temperature active, oscillation-free PdNi(alloy)/Ni-foam catalyst with enhanced heat transfer for coalbed methane deoxygenation via catalytic combustion

Abstract A high-performance PdNi(alloy)/Ni-foam catalyst to be used for coalbed methane (CBM) deoxygenation via catalytic combustion was developed with the aid of galvanic deposition of Pd nanoparticles onto the monolithic Ni-foam followed by in-situ reaction-induced Pd-Ni alloying. The investigations concerning the preparation/reaction conditions and heat/mass transfer indicated that such PdNi(alloy)/Ni-foam catalyst provided a unique combination of high low-temperature activity/selectivity, oscillation-free, high permeability and enhanced heat transfer. As an example, the catalyst with a low Pd-loading of 1 wt% could deliver a complete O 2 conversion for a simulated feed of CH 4 /O 2 /N 2 (40/3/57, vol%) at 350 °C with a high gas hourly space velocity of 12,000 mL g cat. −1  h −1 , and particularly, this catalyst was stable for at least 500 h without deactivation and reaction oscillation. In-situ reaction-induced Pd-Ni alloying was clearly revealed and by nature was responsible for the low-temperature activity (expressed by turnover frequency) promotion and oscillation suppression. The underlying mechanism for CBM deoxygenation over the PdNi(alloy)/Ni-foam catalyst is proposed to be a Langmuir-Hinshelwood type.