Stability of Ruthenium/Carbon Catalytic Materials during Operation in Carbon Monoxide Methanation Process

Abstract

The stable activity of catalysts is an important characteristic, which determines their suitability for industrial applications. The purpose of this study was to investigate the stability of ruthenium systems deposited on carbon under conditions simulating long-term operation in CO methanation. Two series of Ru/carbon catalysts were prepared and studied during CO methanation in a hydrogen-rich gas stream. Two graphitized carbons substantially differing in their surface area (23 and 1457 m2/g) were used as supports, and Ru loadings of 3 and 6 wt.% were applied. The stability of Ru/C catalysts was examined in a 240 h time-on-stream test. The samples were characterized by CO chemisorption, XRD, TEM, Raman spectroscopy, TG–MS studies and CO-TPD. The stability of the catalysts over 240 h in the CO + H2 mixture depended on the support type and Ru loading. The highest CO conversion and increased activity was observed for both catalysts with Ru dispersion above 80%. The tested systems were also resistant to carbon deposition. Interestingly, a similar level of activity was obtained for 3 wt.% Ru supported on the low surface area carbon. It is presumed that the similar activity observed for systems with such different ruthenium dispersion is related to the presence of active sites of different strength and structure on the surface of both small and large Ru particles.

An Outlook on the Applications of Ru-Based Nanocatalysts for CO2 Hydrogenation to CO and CH4

“…244−247 Resultantly, the techno-economic challenges associated with CO 2 methanation are more difficult to overcome, making a transition to generate CO in industry somewhat more desirable, given the vast number of products that can be generated from it via hydrogenation, 10−13 including methane. 248 Therefore, the CO 2 hydrogenation process can be commercialized with Ru/C catalysts, membranes, and electrolysis to sustainably and feasibly collect and react recycled CO 2 and fresh H 2 .…”

“…However, CH 4 and CO prices are expected to recover from such major financial burdens. Despite the high CO price, the issues with generating methane (or synthetic natural gas, SNG) in industry are mainly due to the large H 2 consumption requirements and correspondingly the high H 2 production costs from electrolysis, and generating more renewable methane, such as from captured CO 2 or green electrolysis, will only drive up the costs. − Resultantly, the techno-economic challenges associated with CO 2 methanation are more difficult to overcome, making a transition to generate CO in industry somewhat more desirable, given the vast number of products that can be generated from it via hydrogenation, − including methane . Therefore, the CO 2 hydrogenation process can be commercialized with Ru/C catalysts, membranes, and electrolysis to sustainably and feasibly collect and react recycled CO 2 and fresh H 2 .…”