DFT studies of dry reforming of methane on Ni catalyst

Communication: Enhanced dissociative chemisorption of CO2 via vibrational excitation

“…25 However, the vibration of both methane and water involves light atoms (H), resulting in very slow intramolecular vibrational energy redistribution (IVR), and as a result, mode specific reactivity is readily understood. 26 It is however unclear if such vibrational mode specificity remains robust in the DC of heavier molecules such as CO 2 .…”

“…Here, we report the first theoretical study to explore the vibrational state specific DC dynamics of CO 2 36 the nine-dimensional global DC PES for CO 2 on the rigid Ni(100) surface is developed using the permutation invariant polynomial-neural network (PIP-NN) approach. 38 Since the surface periodicity and molecular permutation symmetry are rigorously enforced, a faithful fit of the global PES with a relatively small number of points can be achieved.…”

“…Besides efforts to reduce fossil fuel consumption and CO 2 capture, various sustainable carbon-neutral strategies have been proposed. 1 For example, CO 2 can be converted through dry reform of methane to syngas (CO 2 + CH 4 → 2H 2 + 2CO), 2 a versatile feedstock for producing many value-added chemicals including renewable fuels, thus closing the carbon cycle. 3,4 As expected, the direct conversion of gaseous CO 2 to CO is difficult due to its high endothermicity.…”

CH4 and CO2 partial pressures influence and deactivation study on the Catalytic Decomposition of Biogas over a Ni catalyst

“…On the other hand, at P CO2 <0.25 (CH 4 :CO 2 molar ratio>1), even though the amount of C * in the catalyst surface is expected to be constant since P CH4 is fixed at 0.25 atm, the amount of O * produced from CO 2 decomposition reaction {4} decreased as P CO2 did, explaining the decrease in (-r CO2 ). Even though, RWGS {10} could influence on (-r CO2 ), it is considered quasi-equilibrated in DRM [16,17] and therefore, an important influence on (-r CH4 ) and (-r CO2 ) is not expected.…”

“…Nowadays, a general rate expression is not yet established for the CH 4 -CO 2 reaction and different expressions can be found in the literature [11][12][13][14][15][16]. However, there is a general consensus on the elementary reaction steps [17]: CH 4 decomposition takes place on the leading face of the catalyst particle (active face), initially generating CH x * species and then chemisorbed carbon (C * ) and atomic hydrogen (H * ) {1-3}. At the same time, direct CO 2 decomposition {4} takes place followed by C * and CH x * oxidation {5-6}, CO generation {7-8}, H 2 generation {9} and the reverse water gas shift reaction {10}.…”