Zn‐Al hydrotalcite‐derived Co x Zn y AlO z catalysts for hydrogen generation by auto‐thermal reforming of acetic acid

Summary Auto‐thermal reforming (ATR) of acetic acid (HAc) is considered as a promising route for hydrogen generation from renewable resources, while oxidation, coking, and sintering need to be addressed for durable catalysts in ATR. In the current work, Zn‐Al hydrotalcite‐derived Co x Zn y AlO z catalysts were prepared by co‐precipitation and evaluated in a fixed‐bed tubular quartz continuous‐flow reactor. The Co 0.70 Zn 3.30 AlO 5.5 ± δ catalyst presented a HAc conversation near 100% and a stable hydrogen yield near 3.01 mol‐H 2 /mol‐HAc. The characterization results of XRD, H 2 ‐TPR, BET, SEM, XPS, and TG indicated that the hydrotalcite structure was obtained via co‐precipitation method; over the hydrotalcite‐derived mixed oxides, (a) the specific surface area was increased with high dispersion of Co, (b) the phases of ZnO with spinel of ZnAl 2 O 4 ,CoAl 2 O 4 , Co 3 O 4 , and ZnCo 2 O 4 were beneficial to improve resistance to coking and oxidation, and (c) the relative stability of Co species over ZnO and spinel phases helps to suppress sintering. Meanwhile, ratio of O/C and temperatures near 0.28 and 650 °C, respectively, were also evaluated and proposed as optimized conditions for hydrogen generation, and the durable Co 0.70 Zn 3.30 AlO 5.5 ± δ catalyst produced a rate of 114.9 mmol‐H 2 /s/g‐catalyst in a 15‐hour ATR test, showing promising potential for hydrogen generation.