Role of Ca, Cr, Ga and Gd promotor over lanthana‐zirconia–supported Ni catalyst towards H₂‐rich syngas production through dry reforming of methane

Abstract

Hydrogen production through methane dry reforming holds the promise of lowering greenhouse gases, that is CO2 and CH4, concentrations. Herein, Ca‐, Cr‐, Ga‐ and Gd‐promoted lanthana‐zirconia–supported Ni catalysts are investigated and characterized by X‐ray diffraction, Raman, infrared and UV‐vis spectroscopy, CH4‐temperature programmed surface reaction and cyclic reduction‐desorption experiment. All promoted catalyst systems had high and constant hydrogen yield (>70%) due to pronounced reoxidation capacity of reduced ‘NiO species strongly interacted with support’ through oxygen replenishment by CO2. The presence of mixed oxide and regeneration of reduced catalyst up to optimum level through oxygen replenishment by CO2 in Gd, as well as Cr‐promoted catalyst, outperformed (80% initially) than other promotors, Ca and Ga. In the long run (440 min to 33 h), Cr‐promoted catalyst system performed better than Gd‐promoted catalyst system as H2 yield remained constant ~79% due to the smallest energy gap between valance and conduction band, Ni‐Cr interaction species for wide range CH4 decomposition and chromate species for profound carbon deposit oxidation.

Chemical Looping Dry Reforming of Methane over Ni-Modified WO3/ZrO2: Cooperative Work of Dispersed Tungstate Species and Ni over the ZrO2 Surface

“…The peaks specified for monoclinic ZrO 2 were observed at 306, 345, 378, 534, 554, and 614 cm –1 , while the peak at 329 cm –1 was attributed to tetragonal ZrO 2 . The peaks at 473 and 634 cm –1 were assignable to both monoclinic and tetragonal ZrO 2 . − These observations showed the presence of both phases, which is consistent with the results of XRD.…”

Barium-Promoted Yttria–Zirconia-Supported Ni Catalyst for Hydrogen Production via the Dry Reforming of Methane: Role of Barium in the Phase Stabilization of Cubic ZrO2

“…Among the different catalysts synthesized in this study, the 5Ni4Ba/YZr catalyst showed the highest hydrogen formation rate (1.14 mol g –1 h –1 ). On the basis of the results in Table S3 , it seems that the Ba promoter is a better choice than Ga, 94 Mn, 95 Al, 49 Al–Mn, 49 Pr, 44 Sm, 37 and Nd 44 promoters in terms of achieving a high hydrogen formation rate. At a ≤5 wt % Ni loading, a >0.9 H 2 /CO ratio, and a ≤0.1 g catalyst weight, Sc-, 20 La-, 41 Gd-, 48 and Ce 109 -promoted ordered mesoporous silica-supported Ni catalyst systems demonstrated a higher rate of H 2 formation than our catalyst system.…”

“…The catalytic activity of the above-discussed DRM catalysts and the other set of 54 DRM catalysts − in terms of the H 2 yield, H 2 formation rate, and CO formation is shown in Table S3. The calculation details for hydrogen and CO formation rates are described in Supporting Information S2.…”

Hydrogen Production from Gadolinium-Promoted Yttrium-Zirconium-Supported Ni Catalysts through Dry Methane Reforming

“…A chromium-promoted lanthana-zirconia-supported system stabilized the tetragonal ZrO 2 phase, stabilized the lanthana-zirconia phase, and showed excellent oxygen replenishment capacity as reduced NiO was re-oxidized by CO 2 up to the optimum level. It showed about 80% H 2 yield . The promotional addition of Ce over the tungsten-zirconia support also had a stable tetragonal zirconia phase .…”