Methanol Steam Reforming over La1-xSrxCeO3-δ Catalysts for Hydrogen Production: Optimization of Operating Parameters

Abstract

In this study, a series of A-site strontium-doped La1-xSrxCeO3-δ (x = 0.2, 0.4, 0.6, 0.8) perovskite catalysts were synthesized via the ethylenediaminetetraacetic acid (EDTA) sol-gel method for hydrogen production by methanol steam reforming. The fresh and the reduced catalysts are characterized by scanning X-ray (XRD), energy dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM) techniques. Results showed that La0.6Sr0.4CeO3-δ exhibited the best performance among the La1-xSrxCeO3-δ catalysts. The operating parameters were optimized to study the catalytic performance of La0.6Sr0.4CeO3-δ, including catalytic temperature, water–methanol ratio (W/M) and liquid hourly space velocity (LHSV). However, the excessive strontium content led to a decrease in hydrogen production amount per unit time, and the high W/M promoted the reverse water–gas shift reaction (RWGS), which resulted in a decrease in CO selectivity and an increase in CO2 selectivity. In addition, the optimal reaction parameters are as follows: reforming temperature of 700 °C; W/M of 3:1; LHSV of 20 h−1. Furthermore, the methanol conversion rate of La0.6Sr0.4CeO3-δ can reach approximately 82%, the hydrogen production can reach approximately 3.26 × 10−3 mol/g(cat)/min under the optimum reaction conditions. Furthermore, La0.6Sr0.4CeO3-δ exhibits high hydrogen selectivity (85%), which is a promising catalyst for MSR application.

Hydrogen-Rich Gas Production by Steam Reforming and Oxidative Steam Reforming of Methanol over La0.6Sr0.4CoO3−δ: Effects of Preparation, Operation Conditions, and Redox Cycles

“…The results evidenced a remarkable catalytic activity due to the stability of Co particles, which were highly dispersed in their reduced state. Similarly, Chen et al recently reported a series of A-site Sr-doped La 1– x Sr x CeO 3−δ ( x = 0.2, 0.4, 0.6, 0.8) perovskite catalysts for H 2 production by SRM, showing that La 0.6 Sr 0.4 CeO 3−δ exhibited the best performance at optimal reaction conditions. In summary, Sr-substituted lanthanum–cobalt oxide perovskites may be potential catalytic precursors for the SRM and OSRM processes to supply H 2 -rich gas for SOFC applications.…”

Perovskite Catalysts for Biomass Valorization

“…However, it is expected that instability under high temperature reducing environments will be generally observed, and such materials should be considered as "perovskite-derived" catalysts. Nevertheless, Chen et al demonstrated that (La 0.6 Sr 0.4 )CeO 3-δ is stable toward 600 °C reduction under 10 vol % H 2 , 199 possibly reflecting the higher stability of (La 0.6 Sr 0.4 )CeO 3-δ cubic perovskites to reducing environments. 200 Gallego et al also investigated the stability of LaNiO 3 and LaFeO 3 perovskites under reducing environments at 900 °C, 201 noting that although the former decomposed to Ni/La 2 O 3 the latter was almost unchanged.…”

“…However, it is expected that instability under high temperature reducing environments will be generally observed, and such materials should be considered as “perovskite-derived” catalysts. Nevertheless, Chen et al demonstrated that (La 0.6 Sr 0.4 )­CeO 3‑δ is stable toward 600 °C reduction under 10 vol % H 2 , possibly reflecting the higher stability of (La 0.6 Sr 0.4 )­CeO 3‑δ cubic perovskites to reducing environments . Gallego et al.…”

Perovskite-Derivative Ni-Based Catalysts for Hydrogen Production via Steam Reforming of Long-Chain Hydrocarbon Fuel

“…Owing to the extremely important role of the support in the catalyst system, it can not only promote the dispersion of active components, but also suppress the sintering of active metals when there is a strong interaction between the support and metal. Among them, perovskite (ABO 3 ) supports are a widely used type of support [37][38][39]. Its A and B sites can be finely regulated and substituted, and it has very high sintering resistance, showing good application prospects in many fields [40].…”