A bridge between trust and control: computational workflows meet automated battery cycling.

Compliance with good research data management practices means trust in the integrity of the data, and it is achievable by full control of the data gathering process. In this work, we demonstrate tooling which bridges these two aspects, and illustrate its use in a case study of automated battery cycling. We successfully interface off-the-shelf battery cycling hardware with the computational workflow management software AiiDA, allowing us to control experiments, while ensuring trust in the data by tracking its provenance. We design user interfaces compatible with this tooling, which span the inventory, experiment design, and result analysis stages. Other features, including monitoring of workflows and import of externally generated and legacy data are also implemented. Finally, the full software stack required for this work is made available in a set of open-source packages.

Enabling Direct Photoelectrochemical H2 Production using Alternative Oxidation Reactions on WO3.

The efficient and inexpensive conversion of solar energy into chemical bonds, such as in H2 via the photoelectrochemical splitting of H2O, is a promising route to produce green industrial feedstocks and renewable fuels, which is a key goal of the NCCR Catalysis. However, the oxidation product of the water splitting reaction, O2, has little economic or industrial value. Thus, upgrading key chemical species using alternative oxidation reactions is an emerging trend. WO3 has been identified as a unique photoanode material for this purpose since it performs poorly in the oxygen evolution reaction in H2O. Herein we highlight a collaboration in the NCCR Catalysis that has gained insights at the atomic level of the WO3 surface with ab initio computational methods that help to explain its unique catalytic activity. These computational efforts give new context to experimental results employing WO3 photoanodes for the direct photoelectrochemical oxidation of biomass-derived 5-(hydroxymethyl) furfural. While yield for the desired product, 2,5-furandicarboxylic acid is low, insights into the reaction rate constants using kinetic modelling and an electrochemical technique called derivative voltammetry, give indications on how to improve the system.

Direct photoelectrochemical oxidation of hydroxymethylfurfural on tungsten trioxide photoanodes.

An important target reaction for solar-powered biomass valorization is the conversion of 2,5-hydroxymethylfurfural (HMF) into key monomers for polyester production. Herein, photoanodes of WO3 are demonstrated to directly photo-oxidize HMF in aqueous electrolyte (pH 4) under simulated solar illumination. The addition of 5 mM HMF increases the saturation photocurrent by 26% and suppresses the water oxidation reaction, as determined by rotating ring-disk electrode experiments. Prolonged photoelectrochemical oxidation (64 h) illustrates system robustness and confirms the production of furandicarboxaldehyde (DFF), furandicarboxylic acid (FDCA), and related intermediates. Quantification of the reaction rate constants via a kinetic model gives insight into the modest DFF and FDCA yields (up to 4% and 1%, respectively)-which is due to the formation of by-products-and suggests routes for improvement.

Tuning the reactivity of copper complexes supported by tridentate ligands leading to two-electron reduction of dioxygen.

A series of copper complexes bearing polypyridyl tridentate ligands have been prepared to fine tune their reactivity toward the oxygen reduction reaction (ORR). During the process of preparation of our copper complexes, we successfully obtained two new crystal structures which are [Cu2(µ-Cl)2(adpa)2](ClO4)2 (2b) and [Cu2(addpa)(CH3CN)2(ClO4)2](ClO4)2 (3a) and a new structure [Cu2(addpa)(CH3CN)2(H2O)2](ClO4)4 (3b) captured after the catalytic ORR. Electrochemical studies and stoichiometric chemical reduction of copper(ii) complexes by ascorbic acid indicated that the presence of an anthracene unit helps to facilitate the reduction of Cu(ii) as well as the stabilisation of Cu(i) species. Regarding oxygen activation, the dinuclear Cu(i) complex 3a showed significantly higher ORR activity than its analogous mononuclear complex 2a. Complex 3a was also found to be relatively robust and competent in catalytic O2 reduction. The observed H2O2 product after this catalysis, together with the data obtained from DFT calculations supported that 3a exhibited a 2H+, 2e- catalytic activity towards the ORR as opposed to the expected 4H+, 4e- process usually found in copper complexes with tridentate ligands. The proton (H+) source for this process was expected from ascorbic acid which also serves as a reducing agent in this reaction. This work highlighted an approach for tuning the ORR activity of the copper complexes by the introduction of a conjugated-π moiety to the supporting ligand.