The role of surface oxidation and Fe–Ni synergy in Fe–Ni–S catalysts for CO₂ hydrogenation

Abstract

Increasing carbon dioxide (CO2) emissions, resulting in climate change, have driven the motivation to achieve the effective and sustainable conversion of CO2 into useful chemicals and fuels. Taking inspiration from...

Fast Microwave Synthesis of Phase-Pure Ni2FeS4 Thiospinel Nanosheets for Application in Electrochemical CO2 Reduction

“…Hence, sulfates are clearly present on the sample surface. Observed signals are in good agreement with the XPS profile of violarite reported by Mitchell et al . The presence of sulfur in the reaction product is moreover confirmed by energy-dispersive X-ray (EDX) spectroscopy, as well as the homogeneous distributions of incorporated elements (Figures S6 and S7).…”

“…The reaction was, however, carried out in oleylamine under nitrogen atmosphere. 11 12 Generally, compared to traditional hydrothermal syntheses, microwave syntheses offer several advantages, such as significantly shortened reaction times, efficient heating, reproducibility, and improved yields. 13 In this context, we present a novel and fast microwave-assisted sol−gel synthesis for the preparation of synthetic violarite.…”

“…Mitchell et al presented a 12 h batch synthesis at 310 °C for the preparation of phase-pure (Ni,Fe) 3 S 4 powders, based on nickel­(II) acetylacetonate, iron­(II) acetylacetonate, and sublimed sulfur. The reaction was, however, carried out in oleylamine under nitrogen atmosphere . An et al described an alternative two-step pathway for the synthesis of NiFe 2 O 4 /Ni 2 FeS 4 heterostructured nanosheets .…”

“…For the one-step microwave synthesis of phase-pure Ni 2 FeS 4 (Scheme , for experimental details see SI), stoichiometric amounts of nickel­(II) acetylacetonate and iron­(III) acetylacetonate were dissolved in 10 mL of a mixture of rac -1-phenylethanol and benzyl mercaptan. The reaction was performed in a microwave reactor under constant stirring at 200 °C for only 30 min, which is the shortest reaction time for the preparation of synthetic phase-pure Ni 2 FeS 4 reported ever. − The obtained powder was precipitated with n -pentane, washed with acetone–water mixtures and diethyl ether, and finally dried at 80 °C. During the reaction, reduction of Fe 3+ and oxidation of Ni 2+ occur, which might involve benzyl mercaptan acting as electron shuttle.…”

An air-stable, reusable Ni@Ni(OH)2nanocatalyst for CO2/bicarbonate hydrogenation to formate

“…This discrepancy in activity might be induced by an inhibited reverse reaction, namely the equilibrium of formate decomposition being suppressed by the presence of gaseous CO 2 and abundant OH − in the solution. The activity is higher than that previously observed with Ni 3 S 4 catalyst under similar conditions (~1 μmol/g cat /h, reaction condition: 125 °C, 2MPa, CO 2 /H 2 = 1:1), 65 but lower than those of Ni 45 and Ni-Zn 9 catalysts at 200 C. GC analysis indicates the absence of volatile organic compounds such as methanol or acetic acid after reaction (Fig.…”