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

Abstract

CO selective methanation (CO-SMET) is an efficient hydrogen purification technology for proton exchange membrane fuel cells. The development of nonnoble metal-based catalysts is quite essential and imperative for CO-SMET and has received considerable interest. Herein, a Zr-promoted nickel-rich spinel-supported Ni catalyst (Ni-ZrO 2 /NiAl 2 O 4 ) was acquired by an epoxidedriven sol-gel process and associated co-impregnation method. The usage of ZrO 2 could enhance the reducibility of the Ni oxides and promote the formation of small Ni particles size, then effectively increase the sorption capacities for both H 2 and CO and facilitate the CO dissociation from catalyst surfaces.All these endowed the catalyst with excellent catalytic performance for CO-SMET, which could lower the CO outlet level to less than 10 ppm with the selectivity higher than 50% within a large temperature window (185 C-255 C).Additionally, the catalyst was highly stable with no obvious carbon deposition or performance degradation during the long-term stability test. This work offers a new technical route to build highly efficient nickel-rich spinelsupported catalysts in the production of high-quality hydrogen.

RuNi/MMO Catalysts Derived from a NiAl-NO3-LDH Precursor for CO Selective Methanation in H2-Rich Gases

“…The high-temperature (300-600 • C) peak is assigned to the bridgebonded adsorptive CO [28]; it is generally believed that bridged chemical adsorption contributes more to the formation of CH 4 than single-site chemisorption [51]. In contrast to the RuNi/MMO-C catalyst, the peak position of bridge-adsorbed CO shifted from 436 • C to 449 • C for RuNi/MMO-N, indicating a stronger interaction between the active sites of RuNi/MMO-N and CO [6]. The enhanced CO adsorption capacity of the RuNi/MMO-N catalyst, which was confirmed by the enhanced peak area of CO-TPD (Figure 6), provides strong evidence of its superior activity and selectivity in the CO-SMET reaction.…”

“…It is vital to remove as much of the carbon monoxide (CO) as possible and obtain concentrations lower than 10 ppm since the presence of CO can poison the Pt electrode of the PEMFCs and degrade the performance [1][2][3]. CO selective methanation (CO-SMET) is regarded as a potential technology for deep CO removal from H 2 -rich gases because it does not require the addition of extra gas [4][5][6]. Because reforming gas contains approximately 20 vol% carbon dioxide (CO 2 ), CO-SMET is typically accompanied by side reactions of CO 2 methanation and reverse water gas shift (RWGS) [7][8][9].…”