Alloy‐Mediated Ultra‐Low CO Selectivity for Steam Reforming over Cu−Ni Bimetallic Catalysts

Abstract

Steam reforming of simple oxygenated hydrocarbons without CÀC bonds is suitable for small-scale decentralized H 2 production for fuel cells. However, the relatively high CO concentration in H 2 -rich reformates produced by traditional Cu-based catalysts will poison the Pt-based anode in fuel cells. Here, we describe a new approach to the design of CuÀNi bimetallic catalysts based on nickel-phyllosilicate for steam reforming of dimethyl ether (DME). With the tunable formation of the CuÀNi alloy, we can modulate the selectivity of CO and CH 4 in steam reforming and achieve H 2 -rich reformates with an ultra-low concentration of CO (below 1000 ppm). This process only requires simple and low-energy purification pretreatments to meet the requirements of commercial fuel cells. Mechanistic studies reveal that the CuÀNi alloy can adsorb CO, particularly at high temperatures, and simultaneously suppress CO dissociation to methane.

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

“…Since Cu−Ni alloys would produce resolved diffraction lines between those of Cu and Ni depending on their composition, the absence of the specific lines rules out at least the formation of well crystallized alloys with CN 0.1 A‐750, CN 0.2 A‐650 and 0.05NiO/CA (Figure b). The above result is much different from the literature results,, in which CuNi alloy is formed over Cu−Ni bimetallic supported catalysts via pre‐reduction at high temperatures (375–700 °C). Besides, the modified supported catalysts (such as Zn, La, Ce and Zr) show a positive effect in generating Cu + species which is beneficial to promoting the MSR reaction .…”

Achieving efficient and robust catalytic reforming on dual-sites of Cu species

“…However, others still suggest that Cu + could directly catalyze the steam reforming, and speculate that there may exist an optimum cooperation between Cu 0 and Cu + to boost activities,19–21 but this lacks effective evidence. Currently, Cu + species are usually introduced through addition of metal oxides to Cu-based catalysts, and self-redox reaction of copper species under feed and reaction conditions 22–25. The complexity of these systems impairs efforts to identify the exact role of copper.…”

“…Currently, Cu + species are usually introduced through addition of metal oxides to Cu-based catalysts, and self-redox reaction of copper species under feed and reaction conditions. 22 – 25 The complexity of these systems impairs efforts to identify the exact role of copper. In this regard, copper phyllosilicates [Cu 2 Si 2 O 5 (OH) 2 ], providing stable Cu + species under hydrogen-rich conditions in catalytic hydrogenation, 26 – 28 may be adopted as a controllable Cu + -supplier to investigate SR mechanisms.…”

Copper Phyllosilicates-Derived Catalysts in the Production of Alcohols from Hydrogenation of Carboxylates, Carboxylic Acids, Carbonates, Formyls, and CO2: A Review

“…Introducing a secondary metal such as B [95,165], Ag [159], Ni [119,120,135,136,157,166], In [90,115], Zn [86,109,116], La [114,167], Sn [110], Ce [85], or Mo [168] in CuPS allows the activity and stability of CuPS-cat to be enhanced because of the inhibition of Cu sintering and the presence of electron transfer between Cu and dopant. Smaller Cu crystalline and higher dispersion of Cu can be obtained by doping the promoters than those of pristine CuPS after reduction.…”