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Aqueous phase reforming (APR) of ethylene glycol was performed at 225 °C and 30 bar in batch and continuous reaction conditions. The effect on the APR performance by functionalizing carbon supports with nitrogen and adding Mn to Pt-based catalysts was investigated. The presence of nitrogen species on the carbon surface and Mn-addition (PtMn) improved the catalytic activity and promoted H 2 production. XPS results suggest that the enhancement of the catalytic activity may be attributed to charge transfer from platinum to the nitrogen groups and Mn. Pt-based catalysts were stable under the studied reaction conditions, while up to 97 % of the manganese leached into the liquid solution during APR. However, the catalytic activity was maintained even with such significant decrease in Mn content, indicating that only a small amount of Mn is necessary to maintain the promotional effect on Pt during APR. [Display omitted] • Electronic interactions between Pt-N and Pt-Mn led to enhanced catalytic activity. • N-doped carbon nanofibers effectively improved H 2 yield in aqueous phase reforming. • Pt-based catalyst promoted with Mn presented higher H 2 yield and selectivity. • Metal-support interactions are key factors in promoting catalytic activity. [ABSTRACT FROM AUTHOR]

[Display omitted] • The electronic structure of V 2 O 3 upon single-atom doping is examined. • A weak Lewis acid-base interaction is found to occur on the pristine surface. • The first dehydrogenation step is identified as the rate-limiting step for PDH. • Mn 1 -V 2 O 3 is suggested to be a good catalyst candidate for PDH. Vanadium-oxide-based catalysts have recently been found very promising for the catalytic dehydrogenation of propane. In this work, self-consistent density functional theory calculations have been performed to examine how the electronic structure of the V 2 O 3 (0001) surface is modified by single-atom doping and how the catalytic properties can be tailored to propane dehydrogenation. The structural stability of single-atom-doped V 2 O 3 (0001) surfaces is assessed by comparing the adsorption energies of single atoms with the cohesive energies of bulk metals. A weak Lewis acid-base interaction is found to occur on the pristine surface, which can be strengthened and weakened by substitution of single atoms for V and O, respectively. On these two types of oxide surfaces, single atoms act as promoters and active sites. The first dehydrogenation step is identified as the rate-limiting step by microkinetic analysis. On all the single-atom-doped surfaces, the activation energy for water formation is higher than that for hydrogen recombination, implying that reduction of the oxide surfaces is difficult to take place during the course of the reaction. If a compromise between the catalytic activity and catalyst selectivity is made, Mn 1 -V 2 O 3 is suggested to be a good candidate as the catalyst for propane dehydrogenation. [ABSTRACT FROM AUTHOR]

Abstract: First-principles calculations have been performed to examine the effect of doped Ag on the kinetics of Ni-catalyzed methane dissociation and coke formation. The close-packed Ag/Ni(111) and stepped Ag/Ni(211) surfaces as well as the defect facets with step sites blocked by Ag or C atoms are constructed to investigate the role of the coordinatively unsaturated sites in the catalytic performance of Ni nanoparticles. The most stable CH x (x =0–4) adsorption configurations and transition states for methane dissociation have been identified on both Ni and Ag/Ni surfaces. The calculated results indicate that the activation energy for methane dissociation is increased with the Ag coverage on Ni(111), and the C atoms deposited on the catalyst surface can be readily separated into small islands by Ag. On Ni(211) Ag atoms are predicted to bind preferentially to the middle-step sites which act as the nucleation center for the growth of filamentous carbon and therefore have the potential to prevent catalyst particles from being destroyed. Meanwhile, as the energy barrier for methane dissociation on the Ag-blocked Ni(211) surface is even higher than that on pure Ni(111), the active center is transferred from the stepped surface to the close-packed surface. These findings provide a rational interpretation of the experimental observations that Ag/Ni catalyst exhibits lower catalytic activity towards steam methane reforming but high resistance to coke deposition. [Copyright &y& Elsevier]