The effect of La substitution by Sr- and Ca- in Ni substituted Lanthanum Zirconate pyrochlore catalysts for dry reforming of methane

Direct conversion of methane to C2 hydrocarbons using W supported on sulfated zirconia solid acid catalyst

“…To understand the deactivation mechanism of W/SZ, TPO was carried out on each spent catalyst from the three temperature runs. Catalytic deactivation is mostly due to carbon deposition [43], which can be categorized as either amorphous, with a peak position at ~ 400 °C, or polymeric carbon generated from aromatics, with peak temperatures at 500-600 °C range, or graphitic carbon with peaks at 650-750 °C range [44].…”

Effect of Preparation Method and Ni2+ Substitution on the Structural, Thermal, and Optical Properties of Nanocrystalline Lanthanum Zirconate Pyrochlore

“…A 2 B 2 O 7 pyrochlores are typically inactive as bulk materials. However, because of their high structural and chemical flexibility, their inherent properties and defined structure can be tempered on both the A and B sites by substitution with other cations with different oxidation states and oxygen by other anions (e.g., S, P, F), which gives rise to various interesting changes in the thermal stability and the electronic and synergistic properties produced by the doping of a second metal [5][6][7][8][9]. Because of these changes, recently, pyrochlores have drawn great attention among researchers because of their multiple applications, such as for superconductivity, batteries, ferroelectricity, water spitting, photocatalysis, photoluminescence, as well as their laser, fuel cell, and magnetic capacities [8,[10][11][12][13][14][15].…”

“…Because of these changes, recently, pyrochlores have drawn great attention among researchers because of their multiple applications, such as for superconductivity, batteries, ferroelectricity, water spitting, photocatalysis, photoluminescence, as well as their laser, fuel cell, and magnetic capacities [8,[10][11][12][13][14][15]. They have proven high-temperature stability in various applications, such as in gas-turbine thermal-barrier coatings and the endothermic dry reforming of the methane (DRM) reaction, and they near 1000 • C for syngas and H 2 production [6,7,16,17]. Most of these nanostructures, such as Bi 2 Ti 2 O 7 , La 2 Ti 2 O 7 , and Ln 2 Zr 2 O 7 , have high-temperature piezoelectric properties since they have high curie points and superior thermal stability [18].…”

“…Therefore, many researchers are focused on the fabrication and design of pyrochlores by the modification of the abovementioned factors. Among the pyrochlores, lanthanide zirconates (LnZr 2 O 7 ) are the multifunctional class of materials that have been applied in diverse fields, such as thermal-protective-coating materials, diesel engines, as catalysts, in nuclear waste disposal, and so on [6][7][8][9][10][11][12][13][14][15][16][17][18][19]. They have been synthesized by solid-state, combustion, hydrothermal, electrolysis, the Pechini process, thermal-impedance, evaporation-induced self-assembly methods, and so on [20][21][22][23][24][25][26].…”

“…F. X. Zhang et al [5] fabricated uranium-doped gadolinium zirconates by a high-temperature wet chemical method and investigated the structural, as well as the bonding environmental changes under the pressure range ambient of 40 GPa. James J. Spivey et al [6,7] prepared face-centered cubic Rh-, Sr-, Ni-, and Ca-substituted lanthanum zirconate by a modified Pechini process and utilized it for the syngas production by DRM. Sven Urban et al [19] fabricated single-phase Ce 2 Zr 2 O 7 , prepared by the conventional solid-state method.…”