Methanol Synthesis at a Wide Range of H₂/CO₂ Ratios over a Rh‐In Bimetallic Catalyst

Abstract

There is increasing interest in capturing H2 generated from renewables with CO2 to produce methanol. However, renewable hydrogen production is expensive and in limited quantity compared to CO2. Excess CO2 and limited H2 in the feedstock gas is not favorable for CO2 hydrogenation to methanol, causing low activity and poor methanol selectivity. Now, a class of Rh‐In catalysts with optimal adsorption properties to the intermediates of methanol production is presented. The Rh‐In catalyst can effectively catalyze methanol synthesis but inhibit the reverse water‐gas shift reaction under H2‐deficient gas flow and shows the best competitive methanol productivity under industrially applicable conditions in comparison with reported values. This work demonstrates a strong potential of Rh‐In bimetallic composition, from which a convenient methanol synthesis based on flexible feedstock compositions (such as H2/CO2 from biomass derivatives) with lower energy cost can be established.

Novel Heterogeneous Catalysts for CO2 Hydrogenation to Liquid Fuels

“…Various bimetallic materials including Pd–Cu, 53 − 55 Pd–Ga, 56 , 57 Pd–In, 58 − 60 Pd–Zn, 61 Ni–Ga, 62 − 66 In–Rh, 67 In–Cu, 68 , 69 In–Co, 70 In–Ni, 71 , 72 and Ni–Cu 55 , 73 have also been examined for methanol production from CO 2 hydrogenation. Among these catalysts, some non-noble metal-based bimetallics were designed for efficient CO 2 hydrogenation to CH 3 OH at low pressure.…”

Promoting Methanol Synthesis and Inhibiting CO2 Methanation with Bimetallic In–Ru Catalysts

“…Figure 1(b) shows the reduction of Ru occurred between 100 and 300 °C, evidenced by two hydrogen consumption peaks centered around 150 and 200 °C consistent with literature results. 9,10 With a catalyst composition having a nominal In/Ru ratio less than 1, similar peaks are observed between 100 and 300 °C, suggesting In 0.85 Ru 1 is reduced below 300 °C. XRD analysis was performed on prereduced In 0.85 Ru 1 as well as In 0.85 Ru 1 reduced at 300 °C, 450 °C, and 800 °C to provide additional evidence.…”

“…7 Commercial CH 3 OH synthesis catalysts typically require a high H 2 /CO 2 ratio (H 2 :CO 2 ≥ 3) and high pressure (>10 MPa) to improve the methanol selectivity, which increases processing costs. 8,9 Therefore, the identification of new catalyst compositions that avoid methane formation while maximizing CH 3 OH yields during CO 2 hydrogenation with lower H 2 /CO 2 ratio remains a significant challenge.…”

“…Such approaches have been successful with In−Pd and In−Rh alloys, where In was predicted to prohibit the CO methanation pathway. 9,17,18 However, the methanol selectivity for reduced In−Pd alloys was 13%, due to the significant contribution from the reverse water gas shift reaction. 18 It was suggested that the interface between the indium oxide and alloy plays a key role in increasing the methanol selectivity.…”

Recent progress in materials development for CO2conversion: issues and challenges

“…297 Tsang and co-workers demonstrated a Rh-In catalyst for industrially scalable methanol production, and also showed excellent efficiency to inhibit reverse water gas shift under controlled H 2 -deficient flow conditions. 298 Furthermore, photochemical and electrochemical pathways for CO 2 fixation reactions with metal NPs are equally efficient, economic and demanding for sustainable chemistry research. In this regard, several inorganic nanomaterials, TiO 2 , ZnO, CdS, ZnS, SrTiO 3 , etc.…”