Peter Mølgaard Mortensen

We have developed an in situ sample-holder—akin to a quartz-based plug-flow reactor—for vibrating sample magnetometry (VSM) in gas-controlled environments at ambient pressure and temperatures up to ∼1000 °C. The holder matches onto a specific type of vibrating sample magnetometer (Lake Shore model 7404-S), but the principles are applicable to other types of VSM. The holder has been tested on powder samples of Co particles on a MgAl2O4 support in both reducing and oxidizing atmospheres. The results show control of gas composition and sample reduction/oxidation. In comparison with conventional sample cups, the in situ holder shows a similar measurement sensitivity but a better repeatability due to the well-controlled gas atmosphere. Moreover, the in situ holder uses a closed gas tubing system such that the active gas only passes by the sample and it is not in contact with the VSM and oven parts. At the outlet, the gas can be collected for analysis and safe handling.

Utilization of CO₂ is a requirement for a sustainable production of carbon‐based chemicals. The reverse water‐gas‐shift (RWGS) can valorize CO₂ by reaction with hydrogen to produce a synthesis gas compatible with existing industrial infrastructure. Fully electrified reverse water‐gas‐shift (eRWGS™) was achieved using integrated ohmic heating and a nickel‐type catalyst at industrially relevant conditions. Using a feed of H₂ : CO₂ in a ratio of 2.25 at 10 barg, utilizing high temperature operation at 1050 °C allowed for production of a synthesis gas with a H₂/CO ratio of 2.0 and no detectable methane, ideal for production of sustainable fuel by e.g. the Fischer–Tropsch synthesis. Facilitating RWGS through CH₄ as intermediate was found superior to the selective RWGS route, due to higher activity and suppression of carbon formation. The eRWGS™ catalyst is found to provide a preferential emissions‐free route for production of synthesis gas for any relevant H₂/CO ratio, enabling production of sustainable carbon‐based chemicals from CO₂ and renewable electricity with high hydrogen and carbon efficiency.

Utilization of CO₂ is a requirement for a sustainable production of carbon‐based chemicals. The reverse water‐gas‐shift (RWGS) can valorize CO₂ by reaction with hydrogen to produce a synthesis gas compatible with existing industrial infrastructure. Fully electrified reverse water‐gas‐shift (eRWGS™) was achieved using integrated ohmic heating and a nickel‐type catalyst at industrially relevant conditions. Using a feed of H₂ : CO₂ in a ratio of 2.25 at 10 barg, utilizing high temperature operation at 1050 °C allowed for production of a synthesis gas with a H₂/CO ratio of 2.0 and no detectable methane, ideal for production of sustainable fuel by e.g. the Fischer–Tropsch synthesis. Facilitating RWGS through CH₄ as intermediate was found superior to the selective RWGS route, due to higher activity and suppression of carbon formation. The eRWGS™ catalyst is found to provide a preferential emissions‐free route for production of synthesis gas for any relevant H₂/CO ratio, enabling production of sustainable carbon‐based chemicals from CO₂ and renewable electricity with high hydrogen and carbon efficiency.

More-efficient heating: Large-scale production of hydrogen through steam reforming directly produces CO ₂ as a side product. In addition, the heating of reactors through fossil-fuel burning contributes further CO ₂ emissions. One problem is that the catalyst bed is heated unevenly, which renders much of the catalyst effectively inactive. Wismann et al. describe an electrical heating scheme for a metal tube reactor that improves the uniformity of heating and catalyst usage (see the Perspective by Van Geem et al. ). Adoption of this alternative approach could affect CO ₂ emissions by up to approximately 1% of global emissions. Science , this issue p. 756 ; see also p. 734

The tailored chemical synthesis of binary and ternary alloy nanoparticles with a uniform elemental composition is presented. Their dual use as magnetic susceptors for induction heating and catalytic agent for steam reforming of methane to produce hydrogen at temperatures near and above 800 °C is demonstrated. The heating and catalytic performance of two chemically synthesized samples of CoNi and Cu⊂CoNi are compared and held against a traditional Ni‐based reforming catalyst. The structural, magnetic, and catalytic properties of the samples were characterized by X‐ray diffraction, elemental analysis, magnetometry, and reactivity measurements. For induction‐heated catalysts, the conversion rate of methane is limited by chemical reactivity, as opposed to the case of traditional externally heated reformers where heat transport limitations are the limiting factor. Catalyst production by the synthetic route allows controlled doping with miniscule concentrations of auxiliary metals.