The century-old Haber-Bosch process for the production of ammonia from N2 and H2 is an energy demanding and greenhouse gas intensive, high temperature and high pressure, fossil powered process. A contemporary challenge is to replace this unsustainable process by a sustainable one that produces ammonia from N2 and H2O, powered by solar electricity, solar heat or solar photons.
In this Perspective, we present an overview of current research activity and technology development in this area together with a high level energy analysis shown in the graphic of the different ways being explored to achieve the lofty goal of a ‘solar ammonia refinery’.
The full article can be read on the Joule website.
Quite surprisingly, the synthetic version of a naturally occurring iron mineral named after a Nobel laureate (Mössbauerite), which has been previously studied by geologists and soil scientists, was found to be a promising ‘iron only’ electrocatalyst for the oxygen evolution reaction (OER). In a four-way collaboration between the Universities of Bayreuth, Bochum, Munich, and Toronto, the electrocatalytic performance of synthetic mössbauerite is demonstrated to be competitive with the best-known ‘iron only’ electrocatalysts. Significantly, the structure of Mössbauerite offers plenty of opportunities for compositional modifications in the quest for a champion earth-abundant, low-cost, non-toxic electrocatalyst
The full article can be read on the Chemistry A European Journal website.
The current fashion for synthesizing methanol continues to be the high pressure and high temperature heterogeneous catalytic conversion of synthesis gas (CO-H2) using alumina supported nanostructured copper-zinc oxide as the catalyst and fossil fuel to power the process. It is an energy intensive process with a large CO2 greenhouse gas footprint and a deleterious effect on the climate. Thus, it would be highly desirable to produce methanol in a sustainable way and use CO2 as feedstock and solar energy to drive the synthesis. Solar technologies that facilitate the efficient conversion of CO2 and H2 into methanol offer a sustainable path to the production of renewable fuels. Furthermore, since about 30% of all known chemicals come from methanol, the production of solar methanol appears to be a “greener” strategy for the chemical and petrochemical industries. In this breakthrough report in Joule, we present a “solar methanol maker”, a rod-shaped In2O3-x(OH)y nanocrystal superstructure, that can efficiently hydrogenate CO2 to methanol at atmospheric pressure with a methanol selectivity for more than 50%. The remarkable production rate of 0.06 mmol gcat-1h-1 and excellent long-term stability of this catalyst in solar methanol synthesis makes it an interesting candidate for converting CO2 to methanol at an industrial scale in a CO2 refinery.
A preview of the study by Chem be read here, along with the full article on the Joule website.
Artifacts that arise from adventitious carbon contamination of catalysts used in the electrochemical, photochemical and thermochemical reduction of CO2 to synthetic chemicals and fuels (www.advancedsciencenews.com), especially at low total conversions and low conversion rates, can only be authenticated through rigorous 13CO2 isotope-labeling proof-of-product experimentation to avoid the reporting of artifacts. Similarly, in the reduction of N2 to ammonia in aqueous solution using the aforementioned approaches, one must be equally diligent to apply strong checks to prevent the reporting of false-positives that can originate from impurities in the catalysts and N2 feed gas, and which require robust 15N2 isotope labeling to ensure unequivocal identification of the source of the ammonia.
Graphic image courtesy of Chenxi Qian.
The full article can be read on the Advanced Science News website.