Performance Research About Copper-cerium Catalyst Supported On Nitrogen-doped Porous Carbon During Preferential Oxidation Of Carbon Monoxide

The increasingly serious environmental problems have led to a high demand forenvironmentally energy.Hydrogen is regarded as an important energy to support the development of sustainable energy and can be used as the feed gas of proton exchange membrane fuel cells?PEMFCs?.However,the platinum electrode of the battery is poisoned by a small amount of CO?about 1%?remaining in the industrial hydrogen production.Preferential oxidation of carbon monoxide?CO-PROX?is the best choice for removing CO in hydrogen-rich atmosphere.CuO-CeO₂ system is a promising catalyst in terms of both catalytic performance and economy.The use of copper and ceria supported onto another material is related to the fact that the catalytic properties of copper and ceria nanoparticles can be different than those of bulk ceria.ZIF based nano-porous carbon material is a kind of high efficient catalyst or catalyst support because of its adjustable structure,high porosity and large specific surface area.In this work,ZIF sacrificial template was used to prepare nitrogen-doped porous carbon as the support of copper-cerium composite catalysts.The specific contents of the study are as follows:The CuCe/NPC catalysts with rhombic dodecahedron structure were prepared by impregnation method.The results of the study show that all samples have high specific surface area.The oxides are partially embedded in the support structure,resulting in the interaction between the support and the oxides.Cu_xO exists in a highly dispersed state,and some copper ions enter into the lattice of the CeO₂,which facilitates the interaction between the copper and cerium.The CuCe/NPC-t composite catalysts were prepared by changing the calcination temperature.The concentration of Ce³⁺and oxygen defects are closely related to the calcination temperature.The copper species in the samples undergo the reduction path of CuO-Cu₂O-Cu.Copper species with high reduction degree corresponds to low catalytic performance.The presence of nitrogen in the support makes the porous carbon easy to capture the acidic guest molecules,such as CO₂,which makes the catalysts showing poor resistance to CO₂.However,they perform the ability of water resistance.The ZIF-8,ZIF-67 and ZIF-8@ZIF-67 sacrificial templates were pyrolyzed to form porous carbon materials,corresponding to NC,GC and NC@GC.NC shows high specific surface area and high nitrogen content.Highly graphitized GC coated with carbon nanotubes and NC@GC with hollow core-shell structure.The mixed oxides of copper and ceria were loaded on the supports.The catalytic performance is influenced by the dispersion of oxides,the electron transfer at the Cu-Ce contact interface between copper and ceria and the carbothermal reduction of bimetallic oxides.