Indium‐based Catalysts for CO₂ Hydrogenation to Methanol: Key Aspects for Catalytic Performance

Abstract

CO2 hydrogenation utilizing sustainably produced hydrogen and CO2 derived from industrial exhaust gas represents a pivotal technology for chemical energy storage and climate change mitigation. This work aimed to identify the best combination of catalyst support, synthesis method and promotor for In2O3/ZrO2 catalysts in a typical fixed‑bed configuration. Intense characterization using ICP‐OES, XRD, XPS, N2‐physisorption, CO2‐TPD, H2‐TPR and SEM‐EDX provide molecular insights into the different effects caused by various synthesis methods and doping elements. Doping the most promising In2O3/ZrO2 (M‐SG) catalyst with 0.7 wt.% NiO by wetness impregnation using an ethanol/water mixture as a solvent, an increased methanol production rate of 0.497 gMeOH∙ ⋅h‐1 could already be achieved at 250°C. Hereby, the low amount of highly dispersed NiO promotes H2 activation via hydrogen spillover, leading to sustained catalytic activity for 100 hours of time‑on‑stream.

Spatially Resolved Reaction Profiles of CO2 Hydrogenation to Methanol Using In-Based Catalysts in a Compact Profile Reactor

“…An increase of catalyst surface area (80.66 m 2 ·g –1 ) by Ni doping was observed as well, leading to a better accessibility of the reactants. No methanation was observed, which is well in line with the literature. ,, After 90 h time on stream, the active productivity at the reactor outlet increased slightly from 2.96 g MeOH ·g In+Ni –1 ·h –1 to 3.07 g MeOH ·g In+Ni –1 ·h –1 with no apparent deactivation. Besides nickel, other promoter metals such as copper and cerium have been tested as well (Table ).…”

“…Building on the work of Frei et al and Kampe et al, ,, it was shown that nickel-promoted In 2 O 3 /ZrO 2 could enhance the catalytic performance compared to pure In 2 O 3 /ZrO 2 . To determine the spatially resolved difference in catalytic performance, we tested the Ni–In 2 O 3 /ZrO 2 catalyst in the CPR at the same reaction conditions ( p = 50 bar, T = 250 °C, see Figure ).…”

“…Indium-based catalysts have recently been studied extensively as alternative methanol synthesis catalysts by CO 2 hydrogenation. − The ZrO 2 supported In 2 O 3 catalyst also showed high stability, selectivity, and activity for CO 2 hydrogenation to methanol. ,,− In previous studies by Wesner and Kampe et al, the effects of the catalyst support, synthesis method, and metal promoter were identified to be key factors to increase the catalytic performance in the CO 2 hydrogenation to methanol …”

Effect of Ni content on Cu–Mn/ZrO2 catalysts for methanol synthesis from CO2 hydrogenation

“…This was due to the stronger desorption ability of Ni for H 2 compared to that of Cu. 41 Combining this with findings from the literature, H 2 spilled over from Ni to Cu, [42][43][44] thereby providing more desorbed H 2 , which further contributed to the increase in hydrogenation ability.…”

A highly durable catalyst system for hydrogen production from dimethyl ether

“…These values are in good agreement with those reported elsewhere. [58][59][60] Further characterisation of the materials with N 2 -physisorption shows that the catalyst surface, pore volume and average pore diameter decrease with increasing indium content (see Fig. S6 in the ESI †).…”