Optimizing the Ni/Cu Ratio in Ni–Cu Nanoparticle Catalysts for Methane Dry Reforming

Abstract

Methane dry reforming (MDR) converts greenhouse gases into syngas. Exploring active catalysts to achieve stable MDR performance is still a great challenge because of the sintering and carbon deposition that occur at high temperatures. In this study, we rationally synthesized Ni−Cu alloy nanoparticles (approximately 5 nm) and utilized electrostatic adsorption for the MDR reaction. The miniscule alloy catalysts had low carbon deposition and trace sintering features, which contributed to a more active and stable MDR reaction than achievable with a pure Ni catalyst. The performance depended on the Cu/Ni ratio, and the highest performance was obtained at a Cu/Ni weight ratio of 0.5:4, followed by ratios of 0.2:4 and 1.5:4. This is because adding a proper quantity of Cu promoted the activation of CO 2 , which enhanced the transformation of CH x into syngas on Ni atoms, while excessive Cu addition formed individual Cu nanoparticles, which influenced Ni atoms on the surface and made the activation of CH 4 harder. This work not only fabricated miniscule alloy nanoparticles but also demonstrated the importance of the Ni/Cu ratio for enhancing the MDR performance.

Design Strategy, Synthesis, and Mechanism of Ni Catalysts for Methane Dry Reforming Reaction: Recent Advances and Future Perspectives

“…Lower: (A) CH 4 conversion, (B) CO 2 conversion in MDR over the Ni–Cu catalysts. Conditions: CH 4 /CO 2 /N 2 = 3/3/4, GHSV = 60 L/(gh), T = 1023 K. Reprinted with permission from ref . Copyright 2021, American Chemical Society.…”

“…Han et al prepared Ni–Cu/SiO 2 catalysts by SEA for MDR (Figure II) . The nickel and copper ammonia complexes were synthesized in an ammonia solution; SiO 2 was then added to the solution to electrostatically adsorb the complexes.…”

Effects of alloying for steam or dry reforming of methane: a review of recent studies

“…Han et al 145 prepared the Ni-Cu nanoparticles (approximately 5 nm) supported on SiO 2 supports by electrostatic adsorption and investigated the effects of Cu/Ni ratios on activities and stabilities. They described that Ni-Cu/ SiO 2 catalyst showed higher activity and less coke formation than Ni/SiO 2 , but a little sintering was observed.…”

“…Rezaei et al 144 investigated Ni–Cu/Al 2 O 3 catalysts using a microchannel reactor. In addition, Han et al 145 investigated the effects of Ni/Cu ratios in Ni–Cu nanoparticles on SiO 2 supports.…”

Ethanol Dry Reforming over Mn-Doped Co/CeO2 Catalysts with Enhanced Activity and Stability

“…With the rapid development of modern industry, the increasing discharge of carbon dioxide (a primary greenhouse gas) has led to serious environmental pollution, which has greatly prevented sustainable development. − To address this issue, enormous efforts including physical adsorption as well as chemical conversion have been made to accelerate the value-added utilization of CO 2. − Among these, CO 2 reforming with ethanol (dry reforming) to produce industrially important syngas (a mixture of CO and H 2 ) is regarded as one of the most promising routes .…”