Influence of the Microstructure of Ni–Co Bimetallic Catalyst on CO Methanation

Abstract

Bimetallic catalysts have been widely used for CO methanation because of their superior activity and stability. Herein, Ni−Co bimetallic catalysts supported on SiO 2 , xNi−yCo/SiO 2 (x and y refer to the loading of Ni and Co), are fabricated for CO methanation. For 6Ni−9Co/SiO 2 , CO conversion is higher than other catalysts with only Ni and Co or both Ni and Co of different ratios. The stability of the 6Ni−9Co/ SiO 2 is much better in comparison with the 15Ni/SiO 2 and 15Co/SiO 2 . The diffuse reflectance infrared Fourier transform spectroscopy study shows that for both 6Ni− 9Co/SiO 2 and 15Ni/SiO 2 , CHO is generated first. However, the bimetallic Ni−Co catalyst follows a distinctive reaction pathway subsequently: the C−O bond of CHO breaks first and then CH hydrogenates to form CH 4 . However, for 15Ni/SiO 2 , the CHO intermediate first reacts with *H to form CHOH, then C−O breaks, and CH 4 is formed. This work well reveals the relationship between the performance of bimetallic catalysts and their reaction mechanism for CO methanation and sheds light on the further development of other bimetallic catalysts for various applications in catalysis.

Recent Progress in Direct DME Synthesis and Potential of Bifunctional Catalysts

“…In the context of H 2 /CO/CO 2 conversion, microstructured reactors with tailored cooling concepts have been demonstrated for the synthesis of hydrocarbons (methanation [140], Fischer-Tropsch synthesis [141]) and oxygenates, such as methanol synthesis [95] and DME [142]. Allahyari et al [143] have described the performance of microreactors with different coatings (washcoating) of Cu/ZnO/Al 2 O 3 -HZSM-5 catalyst.…”

Zr‐promoted nickel‐rich spinel‐supported Ni catalysts with enhanced performance for selective CO methanation

“…Currently, Ni-based catalysts supported on various materials have been extensively reported in CO-SMET. [7][8][9][10] In particular, Ni/Al 2 O 3 catalyst draws a lot of attention due to the large specific surface area, rich porosity, and excellent stability. 11,12 However, the spinel phase NiAl 2 O 4 is inevitably formed by active Ni and Al 2 O 3 and is hard to be reduced, 13 leading to a decreased amount of active Ni and low catalytic performance.…”

“…Currently, Ni‐based catalysts supported on various materials have been extensively reported in CO‐SMET 7‐10 . In particular, Ni/Al 2 O 3 catalyst draws a lot of attention due to the large specific surface area, rich porosity, and excellent stability 11,12 .…”

Methanation of CO 2 over Ni/clay: Effects of calcination temperature on catalyst properties and reaction intermediates formed

“…8 Noble metal catalysts such as ruthenium and palladium show superior catalytic activity for methanation of CO 2 , but their high manufacturing cost preventing them from large-scale application in industry. 9,10 Thus, the transition metal-based catalysts have been the focus of research due to their acceptable catalytic activity while, most importantly, the much lower cost in manufacturing, [11][12][13][14][15] such as nickel-based and cobaltbased catalyst. Nevertheless, the use of nickel still comes at a cost.…”