Plasma-Assisted Dispersion of Bimetallic Ni–Co over Al2O3–ZrO2 for CO2 Reforming of Methane: Influence of Voltage on Catalytic Properties

Abstract

Glow discharge plasma with different voltages (700, 1000 and 1300 V) has been applied for treatment of Ni–Co/Al2O3–ZrO2 catalyst. Physicochemical properties of the catalysts were investigated by XRD, FESEM, BET and FTIR. Based on characterization results, there was an optimum amount of voltage (1000 V) in which the most uniform morphology, highest surface area and the smallest particle size was observed. On contrary of two other catalysts, 1000 V-treated Ni–Co/Al2O3–ZrO2 catalyst showed amorphous structure for NiO which led to improved dispersion of active phase and strong metal–support interactions. In this catalyst particle size distribution was narrow and average particle size was reported to be 21.2 nm. Dry reforming of methane to syngas using synthesized Ni–Co/Al2O3–ZrO2 nanocatalysts illustrated highest catalyst reactivity in the case of 1000 V-treated Ni–Co/Al2O3–ZrO2 nanocatalyst. This catalyst exhibited 99% feed conversion while 700 and 1300 V-treated catalysts showed 91 and 95% feed conversions at 850 °C, respectively. The H2/CO ratio over 700, 1000 and 1300 V treated catalysts was 0.83, 0.98 and 0.88, respectively.