Preparation of palladium-based catalyst by plasma-assisted atomic layer deposition and its applications in CO2 hydrogenation reduction

Abstract

Supported Pd catalyst is an important noble metal material in recent years due to its high catalytic performance in CO2 hydrogenation. An fluidized-bed plasma assisted atomic layer deposition (FP-ALD) process is reported to fabricate Pd nanoparticle catalyst over γ-Al2O3 or Fe2O3/γ-Al2O3 support, using palladium hexafluoroacetylacetonate as the Pd precursor and H2 plasma as counter-reactant. Scanning transmission electron microscopy exhibits that high-density Pd nanoparticles are uniformly dispersed over Fe2O3/γ-Al2O3 support with an average diameter of 4.4 nm. The deposited Pd-Fe2O3/γ-Al2O3 shows excellent catalytic performance for CO2 hydrogenation in a dielectric barrier discharge reactor. Under a typical condition of H2 to CO2 ratio of 4 in the feed gas, the discharge power of 19.6 W, and gas hourly space velocity of 10000 h-1, the conversion of CO2 is as high as 16.3 % with CH3OH and CH4 selectivities of 26.5 % and 3.9 %, respectively.