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Publications (4 of 4) Show all publications
B. Araujo, R., Rodrigues, G. L., Campos dos Santos, E. & Pettersson, L. G. (2022). Adsorption energies on transition metal surfaces: towards an accurate and balanced description. Nature Communications, 13, Article ID 6853.
Open this publication in new window or tab >>Adsorption energies on transition metal surfaces: towards an accurate and balanced description
2022 (English)In: Nature Communications, E-ISSN 2041-1723, Vol. 13, article id 6853Article in journal (Refereed) Published
Abstract [en]

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.

National Category
Chemical Sciences
Identifiers
urn:nbn:se:su:diva-211677 (URN)10.1038/s41467-022-34507-y (DOI)000882306500023 ()36369277 (PubMedID)2-s2.0-85141711081 (Scopus ID)
Available from: 2022-11-25 Created: 2022-11-25 Last updated: 2023-03-28Bibliographically approved
Yu, X., B. Araujo, R., Qiu, Z., Campos dos Santos, E., Anil, A., Cornell, A., . . . Johnsson, M. (2022). Hydrogen Evolution Linked to Selective Oxidation of Glycerol over CoMoO4—A Theoretically Predicted Catalyst. Advanced Energy Materials, 12(14), Article ID 2103750.
Open this publication in new window or tab >>Hydrogen Evolution Linked to Selective Oxidation of Glycerol over CoMoO4—A Theoretically Predicted Catalyst
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2022 (English)In: Advanced Energy Materials, ISSN 1614-6832, E-ISSN 1614-6840, Vol. 12, no 14, article id 2103750Article in journal (Refereed) Published
Abstract [en]

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. 

Keywords
cobalt molybdate, formate, glycerol oxidation, hydrogen evolution, in situ Raman
National Category
Chemical Sciences Chemical Engineering
Identifiers
urn:nbn:se:su:diva-202600 (URN)10.1002/aenm.202103750 (DOI)000761234600001 ()2-s2.0-85125261064 (Scopus ID)
Available from: 2022-03-10 Created: 2022-03-10 Last updated: 2022-08-30Bibliographically approved
Campos dos Santos, E., Barros Neves de Araujo, R., Valter, M., Salazar-Alvarez, G., Johnsson, M., Bajdich, M., . . . Pettersson, L. G. (2021). Efficient Screening of Bi-Metallic Electrocatalysts for Glycerol Valorization. Electrochimica Acta, 398, Article ID 139283.
Open this publication in new window or tab >>Efficient Screening of Bi-Metallic Electrocatalysts for Glycerol Valorization
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2021 (English)In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 398, article id 139283Article in journal (Refereed) Published
Abstract [en]

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.

Keywords
Biodiesel Industry, Glycerol Eletrochemical Valorization, Microkinetic Modeling, Computational Screening Method, Bi-metallic electrodes
National Category
Chemical Sciences
Identifiers
urn:nbn:se:su:diva-198623 (URN)10.1016/j.electacta.2021.139283 (DOI)000709767900012 ()
Available from: 2021-11-15 Created: 2021-11-15 Last updated: 2021-11-16Bibliographically approved
B. Araujo, R., Martin-Yerga, D., Campos dos Santos, E., Cornell, A. & Pettersson, L. G. M. (2020). Elucidating the role of Ni to enhance the methanol oxidation reaction on Pd electrocatalysts. Electrochimica Acta, 360, Article ID 136954.
Open this publication in new window or tab >>Elucidating the role of Ni to enhance the methanol oxidation reaction on Pd electrocatalysts
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2020 (English)In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 360, article id 136954Article in journal (Refereed) Published
Abstract [en]

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.

Keywords
Electrocatalysis, Methanol oxidation, Density functional theory, Pd catalyst, Energy conversion
National Category
Chemical Sciences
Identifiers
urn:nbn:se:su:diva-187498 (URN)10.1016/j.electacta.2020.136954 (DOI)000576817900004 ()2-s2.0-85090219872 (Scopus ID)
Available from: 2020-12-14 Created: 2020-12-14 Last updated: 2022-08-30Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-3964-2807

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