High specific surface area supports for highly active Rh catalysts: Syngas production from methane at high space velocity

A series of high specific surface area mesoporous supports (CeO2, CeO2-Al2O3, and Al2O3) were synthesized by the surfactant-assisted precipitation method using cetyltrimethylammonium bromide (CTAB) as template. Highly dispersed Rh-based catalysts were prepared by the wetness impregnation technique. The physico-chemical properties of the as-prepared supports and catalysts were investigated by N2-physisorption, CO-chemisorption, XRD, and H2-TPR measurements. Catalytic performance was evaluated towards the methane steam reforming (MSR) reaction up to 300 h of time-on-stream varying temperature (700-800 °C), steam-to-carbon (S/C = 2-3), and space velocity (88-200 SL gcat-1 h-1); turnover frequencies were calculated at each reaction condition. All catalysts exhibited high activity strictly connected with high specific surface area (105-325 m2 g-1) and metal dispersion (34.3-84.0%). Significant enhanced stability was observed for Al2O3-containing catalysts towards the MSR reaction at high space velocity.