Thermocatalytic decomposition of methane over mesoporous nanocrystalline promoted Ni/MgO·Al2O3 catalysts

Determination of optimum Pd:Ni ratio for Pd x Ni 100‐ x / CNT s formic acid electrooxidation catalysts synthesized via sodium borohydride reduction method

“…N 2 adsorption-desorption isotherms was used to characterize the catalysts through calculating their BET surface area, pore volume, and average particle, and the obtained results were summarized in Figure 3. All catalysts exhibited typical type V isotherms with H3 type hysteresis loops, indicating mesoporous structure of the catalysts 46 in accordance with the related International Union of Pure and Applied Chemistry (IUPAC) classification. A horizontal tendency was observed in the isotherms at low relative pressures (P/P 0 < 0.1) proving that there is no micropore in these catalysts.…”

Methane Pyrolysis for CO2‐Free H2 Production: A Green Process to Overcome Renewable Energies Unsteadiness

“…The higher reducibility is related to a hydrogen spillover effect induced by some dopants, such as Pd and Cu. These metals are active sites for the dissociation of hydrogen during the catalyst reduction step prior to the reaction, which facilitates the formation of metallic nickel [63,64,[106][107][108]. Furthermore, the weaker interaction between the metal particles and the support after catalyst doping also contributes to an improved reducibility of the metal species [101,103,106,107].…”

“…In the case of metal catalysts, the carbon produced covers the active sites, causing the rapid deactivation of catalysts and, thus, shortening their lifetime. In addition to this, the sintering of particles occurs at high temperatures and contributes to the activity loss of metal catalysts [60,63,83,91,108,[139][140][141][142][143][144][145][146]. Carbon materials also deactivate faster at higher temperatures.…”

“…It is generally accepted that high GHSVs lead to lower methane conversions [61,65,66,97,108,110,121,147]. This is attributed to the shorter residence time, lower contact efficiency between the gas and the catalyst, and lower amount of methane adsorbed on the active sites when the GHSV is increased [61,65,66,105,108,110,[147][148][149]. In addition to this, high GHSVs cause a faster catalyst deactivation [97,108,147].…”

“…This is attributed to the shorter residence time, lower contact efficiency between the gas and the catalyst, and lower amount of methane adsorbed on the active sites when the GHSV is increased [61,65,66,105,108,110,[147][148][149]. In addition to this, high GHSVs cause a faster catalyst deactivation [97,108,147]. This is due to the higher carbon formation rate compared to the carbon diffusion rate through the particles, which leads to carbon accumulation and consequently catalyst deactivation [150].…”