Electrochemical conversion of glycerol offers a promising route to synthesize value-added glycerol oxidation products (GOPs) from an abundant biomass-based resource. While noble metals provide a low overpotential for the glycerol electrooxidation reaction (GEOR) and high selectivity toward three-carbon (C3) GOPs, their efficiency and cost can be improved by incorporating non-noble metals. Here, we introduce an effective strategy to enhance the performance of Pd nanoparticles for the GEOR by alloying them with Ni. The resulting PdNi nanoparticles show a significant increase in both specific activity (by almost 60%) and mass activity (by almost 35%) during the GEOR at 40 °C. Additionally, they exhibit higher resistance to deactivation compared to pure Pd. Analysis of the GOPs reveals that the addition of Ni into Pd does not compromise the selectivity, with glycerate remaining at around 60% of the product fraction and the other major product being lactate at around 30%. Density functional theory calculations confirm the reaction pathways and the basis for the higher activity of PdNi. This study demonstrates a significant increase in the GEOR catalytic performance while maintaining the selectivity for C3 GOPs, using a more cost-effective nanocatalyst.

Density functional theory predictions of binding energies and reaction barriers provide invaluable data for analyzing chemical transformations in heterogeneous catalysis. For high accuracy, effects of band structure and coverage, as well as the local bond strength in both covalent and non-covalent interactions, must be reliably described and much focus has been put on improving functionals to this end. Here, we show that a correction from higher-level calculations on small metal clusters can be applied to improve periodic band structure adsorption energies and barriers. We benchmark against 38 reliable experimental covalent and non-covalent adsorption energies and five activation barriers with mean absolute errors of 2.2 kcal mol⁻¹, 2.7 kcal mol⁻¹, and 1.1 kcal mol⁻¹, respectively, which are lower than for functionals widely used and tested for surface science evaluations, such as BEEF-vdW and RPBE.

Electrochemical valorization of biomass waste (e.g., glycerol) for production of value-added products (such as formic acid) in parallel with hydrogen production holds great potential for developing renewable and clean energy sources. Here, a synergistic effort between theoretical calculations at the atomic level and experiments to predict and validate a promising oxide catalyst for the glycerol oxidation reaction (GOR) are reported, providing a good example of designing novel, cost-effective, and highly efficient electrocatalysts for producing value-added products at the anode and high-purity hydrogen at the cathode. The predicted CoMoO₄ catalyst is experimentally validated as a suitable catalyst for GOR and found to perform best among the investigated metal (Mn, Co, Ni) molybdate counterparts. The potential required to reach 10 mA cm⁻² is 1.105 V at 60 °C in an electrolyte of 1.0 ᴍ KOH with 0.1 ᴍ glycerol, which is 314 mV lower than for oxygen evolution. The GOR reaction pathway and mechanism based on this CoMoO₄ catalyst are revealed by high-performance liquid chromatography and in situ Raman analysis. The coupled quantitative analysis indicates that the CoMoO₄ catalyst is highly active toward C—C cleavage, thus presenting a high selectivity (92%) and Faradaic efficiency (90%) for formate production. 

Glycerol is a byproduct of biodiesel production and, as such, it is of limited economic value. By means of electrooxidation, glycerol can be used as a feedstock for scalable hydrogen production, in addition to conversion to value-added products. The development of novel and efficient catalytic electrode materials for the anodic side of the reaction is a key towards a hydrogen-based energy economy. In the present study, a computational screening protocol combining DFT, scaling relations, and microkinetic modeling allows for a rational selection of novel catalysts that can deliver efficient glycerol electrooxidation, low cost of production, and environmental sustainability. Activity and chemical selectivity towards hydrogen production on pure metal catalysts is discussed in terms of volcano-shaped plots. We find that the selectivity in the glycerol oxidation reaction is influenced by a different energy landscape when in the presence of water and best classified by a comparison of O-H and C-H bond-breaking barriers. In addition, we screened 3570 bi-metallic catalysts in the AB (L1(0)) and A(3)B (L1(2)) ordered structures for activity, stability, price, and toxicity. By filtering based on the criteria for toxicity, resistance to oxidation, miscibility, and price, we have identified 5 L1(0) structured catalysts (AgPd, AuPd, PtSb, CuPt, and AgPt) and 20 L1(2) catalysts (Ga3Ta, In3Ta, Ir3W, Ir3Mo, Cu3Pt, Ir3Ta, Ir3Re, Pd3Bi, Pd3Cu, Pd3W, Pd3Co, Pd3Sn, Pd3Mo, Pd3Ag, Pd3Ga, Pd3Ta, Au3Ru, Pd3In, Au3Ir, and Pd3Au) that are all predicted to show high activity. We also identify an additional 37 L1(0) and 92 L1(2) structured electrocatalysts with an anticipated medium-high activity.

Glycerol electrolysis affords a green and energetically favorable route for the production of value-added chemicals at the anode and H2 production in parallel at the cathode. Here, a facile method for trapping Pt nanoparticles at oxygen vacancies of molybdenum oxide (MoOx) nanosheets, yielding a high-performance MoOx/Pt composite electrocatalyst for both the glycerol oxidation reaction (GOR) and the hydrogen evolution reaction (HER) in alkaline electrolytes, is reported. Combined electrochemical experiments and theoretical calculations reveal the important role of MoOx nanosheets for the adsorption of glycerol molecules in GOR and the dissociation of water molecules in HER, as well as the strong electronic interaction with Pt. The MoOx/Pt composite thus significantly enhances the specific mass activity of Pt and the kinetics for both reactions. With MoO_x/Pt electrodes serving as both cathode and anode, two-electrode glycerol electrolysis is achieved at a cell voltage of 0.70 V to reach a current density of 10 mA cm⁻², which is 0.90 V less than that required for water electrolysis. 

We compare different means of predicting and rationalizing properties of corrosion films aiming at gaining deeper understanding of the behaviour of copper in aqueous and sulphide-containing environments. Purely geometrical tools ranging from mean bulk information to anisotropic and facet-specific approaches are discussed, and their performances compared against DFT-based stability and property evaluations of a range of interfaces arising from combining low-index crystallographic planes of the compounds Cu, Cu2O, and Cu2S. We demonstrate the necessity to consider facet-specific interactions to understand nanolevel differences between Cu2S and Cu2O film behaviour, and that thin films cannot be directly described by bulk properties.

Glycerol is a byproduct of biodiesel production and an abundant feedstock that can be used for the synthesis of high-value chemicals. There are many approaches for glycerol valorization, but, due to the complicated reaction mechanism, controlling which products are produced is challenging. Here, we describe glycerol's chemical selectivity for different metallic catalysts using descriptors for carbon (mainly *C, *CH2OH) and oxygen (mainly *O, CH3O*). The quality of these descriptors and the weighted combinations thereof are validated based on their fit, via linear regression, to the binding energies of all reaction intermediates generated in the first two glycerol dehydrogenation steps on a number of close-packed Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, and Au surfaces. We show that *CH2OH is a better descriptor than *C for the studied carbon-bound intermediates, which is attributed to the observation that the adjacent *OH group interacts with the surface. This leads to a negative oxygen dependence, which can be generalized to similar alcohol-derived adsorbates. Furthermore, we show that CH3O* is a better oxygen descriptor than *0 for the studied intermediates. This is mainly attributed to the difference between the single and double bonds, as we show that *OH is closer to the accuracy of CH3O*. Multilinear regression with different combinations of *C, *O, and *OH is comparable in accuracy to that of *CH2OH and CH3O*. Scaling relationships are used to determine the selectivity map for glycerol dehydrogenation. The results show that the first dehydrogenation is selective toward two different intermediates (one bonded via the secondary carbon and the other via the secondary oxygen) depending on the relative bond strength of the carbon and oxygen descriptors. The second dehydrogenation step results in five intermediates, again depending primarily on the relative bond strength of carbon and oxygen to the surface. The selectivity maps can be used together with kinetic considerations and experimental data to find catalyst candidates for glycerol dehydrogenation.

The SCC-DFTB repulsion parameters based on the material science set (matsci) were redesigned to describe the structure and dynamic properties of bulk liquid water. The iterative Boltzman inversion (IBI) approach was applied by simultaneously correcting the O-H and O-O SCC-DFTB repulsion energy contribution to develop the new water-matsci and water-matsci-UFF set of parameters. The water-matsci parameters provide O-O and O-H radial distribution functions in excellent agreement with available state-of-the-art experimental data. The parametrization is applied to compute binding energies of a set of water clusters with 2-10 molecules and compared to other DFTB parameters and reference data. The self-diffusion coefficients of ambient and supercooled (254 K) water have been estimated and compared to other SCC-DFTB calculated values and experiment. The performance of the new parameters for describing the density of ambient water and reactions involving water dissociation into H3O+ and OH-, the self-diffusion coefficient, and neutralization energy were investigated. Finally, we show that the new parametrization can be reliably applied to adsorption of water on the mineral pyrite by combining the new water-matsci parameters with the available matsci set of parameters for pyrite. This opens opportunities for investigating materials and phenomena of increasing complexity involving water.

Corrosion of copper is an expensive degradation process of materials in engineered infrastructures and in various technical applications. It is also an important factor in the geological disposal of spent nuclear fuel, where sulfide-induced corrosion is expected to be the predominant chemical degradation process of copper canisters used for encapsulation and isolation of the radioactive material from the biosphere. One aspect of the corrosion process that is still under intense research is the corrosion morphology and how it might be affected by the composition of the groundwater. Using density functional theory, we investigate the electrochemical interface of corroding copper in aqueous solutions containing sulfides, with and without the presence of Cl-, HCO3-, and SO42- anions. Through state-of-the-art electrochemical models, we account for the effects of pH, concentrations, and potential on the interfacial structure and composition. Results are presented for the Cu(110) surface facet and compared to the (110) and (001) facets of chalcocite (Cu2S), i.e., the main product of sulfide-induced corrosion. It is found that at low potentials, H dominates on all surfaces, and at high potentials, sulfides. In the intermediate ranges, the surfaces differ with sulfides prevailing on Cu, while adsorbed H2O, Cl, or H dominate on Cu2S. The results are summarized as surface Pourbaix diagrams and are generally applicable in corrosion science and electrochemistry. The implications of the study are discussed in light of the expected conditions of planned spent nuclear fuel repositories in Sweden, Finland, and Canada.

Amongst promising available technologies enabling the transition to renewable energy sources, electrochemical oxidation of alcohols, in a direct fuel cell or in an electrolysis reaction (H-2 production), can be an economically and sustainable alternative to currently used technologies. In this work, we highlight the advantages of a Pd-Ni bimetallic electrocatalyst for methanol electrooxidation - a convenient choice due to the low cost of Ni combined with the observed acceptable catalytic performance of Pd. We report a synergistic effort between experiments and theoretical calculations based on density functional theory to provide an in-depth understanding - at the atomistic level - of the origin of the enhanced electrochemical activity of methanol electrooxidation using the bimetallic catalysts Pd3Ni and PdNi over pure Pd. Cyclic voltammograms and High-Performance Liquid Chromatography (HPLC) demonstrate higher activity towards methanol electrooxidation with increased Ni concentration and, furthermore, higher selectivity for CO2. These effects are understood by: 1) changes in the methanol oxidation reaction mechanism. 2) Mitigation or suppression of CO poisoning on the Pd-Ni alloys as compared to the pure Pd catalyst. 3) A stronger tendency towards highly oxidized intermediates for the alloys. These findings elucidate the effects of a bimetallic electrocatalyst for alcohol electrooxidation as well as unambiguously suggest PdNi as a more cost-effective alternative electrocatalyst.