Characterization of La-promoted Ni/Al2O3 catalysts for hydrogen production from glycerol dry reforming

In the current paper, dry (CO2)-reforming of glycerol, a new reforming route, was carried out over alumina (Al2O3)-supported, non-promoted and lanthanum-promoted nickel (Ni) catalysts. Both sets of catalysts were synthesized via a wet co-impregnation procedure. Physicochemical characterization of the catalysts showed that the promoted catalyst possessed smaller metal crystallite size, hence higher metal dispersion compared to the virgin Ni/Al2O3 catalyst. This was also corroborated by the surface images captured by the FESEM analysis. From temperature-programmed calcination analysis, the derivative weight profiles revealed two peaks, which represent a water elimination peak at a temperature range of 373 to 473 K followed by nickel nitrate decomposition from 473 to 573 K. In addition, BET surface area measurements gave 85.0 m2·g−1 for the non-promoted Ni catalyst, whilst the promoted catalysts showed an average of 1% to 6% improvement depending on the La loadings. Significantly, reaction studies at 873 K showed that glycerol dry reforming successfully produced H2. The 2%La-Ni/Al2O3 catalyst, which possessed the largest BET surface area, gave an optimum H2 generation (9.70%) at a glycerol conversion of 24.5%.

Graphical AbstractUnder a specific La% promotion and surface area, an optimum result can be obtained. This is due to the factor of promoter and active sites coverage on the catalysts which affect the catalytic activity.Figure optionsDownload full-size imageDownload as PowerPoint slide