Recent Advances in Heterogeneous Catalytic Hydrogenation of CO2 to Methane

Abstract

With the accelerating industrialization, urbanization process, and continuously upgrading of consumption structures, the CO 2 from combustion of coal, oil, natural gas, and other hydrocarbon fuels is unbelievably increased over the past decade. As an important carbon resource, CO 2 gained more and more attention because of its converting properties to lower hydrocarbon, such as methane, methanol, and formic acid. Among them, CO 2 methanation is considered to be an extremely efficient method due to its high CO 2 conversion and CH 4 selectivity. However, the CO 2 methanation process requires high reaction temperatures (300-400°C), which limits the theoretical yield of methane. Thus, it is desirable to find a new strategy for the efficient conversion of CO 2 to methane at relatively low reaction temperature, and the key issue is using the catalysts in the process. The advances in the noble metal catalysts, Ni-based catalysts, and Co-based catalysts, for catalytic hydrogenation CO 2 to methane are reviewed in this paper, and the effects of the supports and the addition of second metal on CO 2 methanation as well as the reaction mechanisms are focused.

Hydrothermal Synthesis of Ruthenium Nanoparticles with a Metallic Core and a Ruthenium Carbide Shell for Low-Temperature Activation of CO2 to Methane

“…The catalysts proposed in patents and in the literature for producing CH4 from CO2 are based on metals like Ni, Ru, Pd, Rh, mono or multimetallic, with or without promoters (Na, K, Cs, rare-earth elements…) on different supports (TiO2, SiO2, Al2O3, CeO2, ZrO2, CNT doped with N). [3][4][5] In all cases high temperatures (300-500 °C) are employed which results in large energy input, high operational costs for large-scale production and with negative impact on catalyst stability. Ru is a highly active metal for CO2 methanation at lower temperature, however the highest space time yield to methane reported up to now does not exceed the 0.9 µmolCH4•s -1 •gcat -1 at 165 °C and 2.6 µmolCH4•s -1 •gcat -1 at 200 °C and atmospheric pressure, obtained at a 1.6 mL•g -1 •s -1 gas feed rate on a Ru/TiO2 catalyst, still too low for industrial application.…”

Recent Advances in Power-to-X Technology for the Production of Fuels and Chemicals

“…Noble metals have also been extensively investigated due to their good catalytic performance for CO 2 methanation at low temperatures and good resistance to carbon formation (Frontera et al, 2017; Qin et al, 2017). Karelovic and Ruiz (2012) studied the performance of Rh/γ-Al 2 O 3 catalyst with Rh content varying between 1 and 5 wt.% at a temperature range of 50–200°C.…”

Ru and Ni—Privileged Metal Combination for Environmental Nanocatalysis

“…They can also easily get deactivated at high temperatures by sintering and/or coke deposition and are particularly susceptible to sulfur poisoning, e.g., from H 2 S [80,91,97]. There are several solutions that can improve the performance and life span of this type of catalyst, for instance, using a support [83,91,[98][99][100], catalytic promoters [91,99,100], coupling with other non-noble elements into alloys or spinel structures [100,101], or composing bimetallics with noble metals [10,53,[74][75][76]84]. Ruthenium is one of the most used noble metals for this purpose.…”

“…Catalyst support is an important issue for determining low-temperature performance [99,100]. The catalyst specified in Table 3 entry 7 is a good example.…”

“…The catalyst specified in Table 3 entry 7 is a good example. In Ce x Zr 1−x O 2 (CeZrO 2 ) supported Ni or Ru-Ni catalysts, it is the high oxygen storage capacity of the CeZrO 2 solid solution together with the presence of highly dispersed metal particles that yields a high efficiency [74,100,109]. In addition, the Ce x Zr 1-x O 2 support is characterized by a large amount of the basic active sites, which improves the chemisorption of the acidic CO 2 and prevents carbon deposition on the catalyst [110].…”