Cu−Ni−Al Spinel Oxide as an Efficient Durable Catalyst for Methanol Steam Reforming

Abstract

Copper metal catalysts suffer from gradual loss of activity due to the agglomeration and sintering of active metals during the catalytic reaction processes. Herein, we show that enhanced catalytic durability for methanol steam reforming (MSR) can be achieved by using Ni modified Cu−Al spinel solid solution as catalysts without pre‐reduction treatment. In so doing, Cu atoms can be gradually released from spinel structure after the initiating of reaction by non‐spinel CuO entities. Incorporation of Ni in the spinel structure reveals two positive effects: slowing down the Cu releasing rate and producing even smaller Cu nanoparticles as compared to that of Cu−Al spinel. Since Ni2+ ions in spinel framework cannot be reduced during the catalytic process, we suggest that the remaining defective CuaNib□cAldO4 spinel structure plays a crucial role in stabilizing the formed Cu nanoparticles. The synthesized sample with 0.05 mol Ni per mol Cu shows the best catalytic performance as demonstrated by pretty stable activity during the long‐term catalytic testing up to 2000 h. The findings show great commercial application potentials for the production of H2 from MSR.

Bimetallic Fe‐Promoted Catalyst for CO‐Free Hydrogen Production in High‐Temperature‐Methanol Steam Reforming

“…Hence, in order to have higher catalytic activity, Fe beyond 6 wt.% corresponding to Cu−Fe (50/50) molar ratio should not be used. The observed no CO formation with Cu−Fe/AZZ is hence much lesser than the recently reported Ni modified Cu−Al spinel which gave CO selectivity of ∼0.5 …”

“…The observed no CO formation with CuÀ Fe/AZZ is hence much lesser than the recently reported Ni modified CuÀ Al spinel which gave CO selectivity of~0.5. [39]…”

Advances in Enhancing the Stability of Cu-Based Catalysts for Methanol Reforming

“…Some new supports, such as KIT-6, exhibit low Cu dispersion, which also reminds us that it is necessary to find an effective new support. To solve the sintering problem of copper-based catalysts, spinel-structured copper-based catalysts have been extensively studied in recent years [43,120,121]. The spinel-structured copper-based catalysts were found to perform in MSR without prereduction [85,122].…”

“…The sustainedrelease catalytic mechanism is a major reason for maintaining the stability of copper-based spinel catalysts. Slow-release catalysis means that the copper species in the catalyst can be gradually released, and the release rate is not fast; thus, the stability is improved [121,123]. Meanwhile, the unreleased Cu 2+ can stabilize these released copper species [124].…”

Effective Low-Temperature Methanol Aqueous Phase Reforming with Metal-Free Carbon Dots/C3N4 Composites

“…The price of methanol is comparatively low, and it can be produced by many kinds of organics . Traditional methanol reforming to generate H 2 needs high temperature (>200 °C) and high pressure (2.5–5.0 MPa), which severely limited its industrial use. − Compared with steam reforming, the liquid vaporization unit can be removed by the water phase reforming, which makes the structure of an in situ H 2 production reactor more compact . Moreover, it can also make good use of the water–gas shift (WGS) reaction to decrease the selectivity of the intermediate product CO .…”