Shaped mesostructured Ni/CeO2 as active catalysts in hydrogen production from acetic acid oxidative steam reforming

Oxidative steam reforming (OSR) of acetic acid was carried out using shaped catalysts prepared by combining Ni supported on mesostructured ceria with various clays (kaolinite, sepiolite, attapulgite, and bentonite). Extrudates of bentonite or attapulgite calcined at a heating rate of 1 °C/min exhibited superior mechanical resistance, with attapulgite also providing higher acetic acid conversion and hydrogen yield. Operating conditions were optimized to minimize concentration gradients by analyzing external mass transfer limitations and internal diffusion resistance (Weisz-Prater criterion<1). The reusability of Ni/m-CeO 2 extrudates prepared with attapulgite (Ni/m-CeO 2 -A), was evaluated through five successive regeneration-reaction cycles at 550 °C and WHSV = 60 h −1 to induce catalyst deactivation by coke deposition. Catalyst's regeneration was performed in-situ under airflow to remove coke deposits, followed by hydrogen flow to reduce NiO and restore the active phase. Notably, initial conversion and hydrogen yield were almost recovered after each regeneration step. • Attapulgite and bentonite significantly improved the mechanical strength of Ni/mCeO 2 -based pellets. • Calcination treatment at 1 °C/min up to 650 °C enhanced pellets the mechanical resistance. • Attapulgite-based pellets (Ni/mCeO 2 -A) reached higher hydrogen yield in acetic acid OSR. • Ni/mCeO 2 -A reusability was tested through regeneration-reaction cycles at 550 °C. • Conversion and H 2 yield were almost recovered after even 5 regeneration cycles.