CO 2 coverage on Pd catalysts accelerates oxygen removal in oxy-combustion systems.
Sungyoon JungTengfei CaoRohan MishraPratim BiswasPublished in: Physical chemistry chemical physics : PCCP (2023)
Oxy-combustion systems result in enriched CO 2 in exhaust gases; however, the utilization of the concentrated CO 2 stream from oxy-combustion is limited by remnant O 2 . CH 4 oxidation using Pd catalysts has been found to have high O 2 -removal efficiency. Here, the effect of excess CO 2 in the feed stream on O 2 removal with CH 4 oxidation is investigated by combining experimental and theoretical approaches. Experimental results reveal complete CH 4 oxidation without any side-products, and a monotonic increase in the rate of CO 2 generation with an increase in CO 2 concentration in the feed stream. Density-functional theory calculations show that high surface coverage of CO 2 on Pd leads to a reduction in the activation energy for the initial dissociation of CH 4 into CH 3 and H, and also the subsequent oxidation reactions. A CO 2 -rich environment in oxy-combustion systems is therefore beneficial for the reduction of oxygen in exhaust gases.
Keyphrases
- density functional theory
- room temperature
- particulate matter
- hydrogen peroxide
- sewage sludge
- electron transfer
- molecular dynamics
- municipal solid waste
- highly efficient
- visible light
- gene expression
- single cell
- nitric oxide
- risk assessment
- dna methylation
- high resolution
- anaerobic digestion
- transition metal
- high speed