Methane dry reforming with CO2 on CeZr-oxide supported Ni, NiRh and NiCo catalysts prepared by sol–gel technique: Relationship between activity and coke formation

Role of MgO over γ-Al2O3-supported Pd catalysts for carbon dioxide reforming of methane

“…They would cover catalyst surface and block accessible Pd active sites, resulting in its fast deactivation. The amorphous carbon on the Pd catalyst could encapsulate exposed active metal particles, resulting in its significant deactivation, similar to the previously reported Ni catalysts [68][69][70][71][72]. In contrast, promoter Mg on Pd catalysts remarkably affects the two main deactivation factors.…”

Coprecipitation versus chemical vapour deposition to prepare Rh/Ni bimetallic catalysts

“…However, it was also reported that the amount of Ni-containing species involved in the Rh/Ni alloy was very low in comparison to the total number of present species; whereas some works reported the formation of Rh/Ni or Ru/Ni clusters by migration of metallic particles [10,25]. The alloy formation was also evidenced by vis-UV/ DR, XPS [50], TEM-EDS [28,51]. On the contrary, Dias and Assaf [12] did not observe any change in the CO adsorption on Ni by CO-DRIFTS spectra, indicating that the noble metal (Pt, Pd or Ir) at low loadings did not modify significantly the electronic properties of Ni.…”

“…On the other hand, the noble metal can be added to a calcined Ni-HT [36,37,46,56]. Moreover, Rh/Ni ceria-zirconia bulk catalysts were prepared by a pseudo sol-gel method [51,57,58] or by firstly introducing Ni during the sol-gel preparation and after impregnating Rh ions [26,30].…”

On the coke deposition in dry reforming of methane at elevated pressures

“…It is obvious that at the high temperatures used for reforming, it is challenging to synthesize thermally stable catalysts and metal particles, which do not exceed the upper limit of 2 nm. Alternative conceptual approaches to enhance catalyst stability such as poisoning of the metal (SPARG process) and other means to reduce buildup of carbon at the catalyst have been vividly explored [9][10][11][12][13].…”