Steam reforming of methanol over structured catalysts prepared by electroless deposition of Cu and Zn on anodically oxidized alumina

Abstract

Steam reforming of methanol (SRM) was investigated over a series of porous structured Cu–Zn/γ-Al2O3/Al catalysts. The porous γ-Al2O3 layer was synthesized on the Al substrate through anodic oxidation in an oxalic acid solution. Cu and Zn in different molar concentrations were loaded using electroless deposition over the prepared γ-alumina support. The synthesized catalysts were characterized using the BET, XRD, SEM, and energy dispersive X-ray analysis. The Cu metal surface area was measured by the selective chemisorption of nitrous oxide. The obtained γ-Al2O3/Al (AAO) had a specific surface area of 27 m2/g, and it was observed that the Al2O3 layer contained well-developed nanopores (∼60 nm), making it ideal for use as a catalyst support. The results showed that the BET surface area of the catalyst linearly decreased with the Cu–Zn loading. The Cu metal surface area increased with increasing copper concentration in the deposition bath solution. A fixed tubular reactor was designed and fabricated to evaluate the catalytic activity of the Cu–Zn/AAO catalysts for SRM. Among the catalysts, Cu(0.06)Zn(0.06)/AAO showed 78% MeOH conversion at 350 °C. MeOH conversion linearly increased with increasing electroless deposition time from 0.5 to 10 min and appeared to plateau thereafter, indicating that 10 min was the optimal loading time.