CATREDOX Group

Abstract

Isolated dual-atom sites constitute a promising yet largely unexplored strategy for directing reaction intermediates in CO₂ hydrogenation to methanol. In this work, we identify isolated Cu+–O–Ga3+ dual-atom motifs and provide a mechanistically consistent interpretation linking them to enhanced methanol synthesis. This finding is elucidated through the combined use of steady-state isotopic transient kinetic analysis (SSITKA) with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and density functional theory (DFT) calculations. Isolated Cu⁺–O–Ga³⁺ pairs, anchored within Cu–Ga–Mg–Al hydrotalcite–derived catalysts, are enabled by ionic-radius compatibility and the preferential Cu+-Ga³⁺ association within the oxide lattice.  X-ray absorption spectroscopy and deep learning-assisted atomic-resolution HAADF-STEM imaging, combined with statistical pair analysis, provide complementary evidence supporting a statistically relevant population of short-range Cu+–O–Ga3+ pairs. Together with the kinetic, spectroscopic, and theoretical analyses, these findings support Cu+–O–Ga3+ proximal motifs as the most plausible structural origin of the enhanced methanol-forming functionality and provide a rational design principle for improved methanol synthesis catalysts.

The CATREDOX Group warmly congratulates Dr. Henrique Gasparetto on the successful defense of his doctoral thesis, entitled “Catalytic Steam Reforming of Ethanol for Onboard Hydrogen Production”.

The thesis was submitted to the Graduate Program in Chemical Engineering at the Universidade Federal de Santa Maria (UFSM), Brazil, to fulfill the requirements for the degree of Doctor in Chemical Engineering, with concentration in Industrial and Environmental Process Development. The defense took place on July 24, 2026.

Advisor: Dr. Nina Paula Gonçalves Salau, Universidade Federal de Santa Maria, Brazil.
Co-advisor: Dr. Patricia Concepción Heydorn, Instituto de Tecnología Química, ITQ, CSIC-UPV, Spain.

The thesis focused on the development of Ni-based inverse catalysts for the low-temperature steam reforming of ethanol, aiming at decentralized and onboard hydrogen production. The work explored catalyst architectures based on Ni nanoparticles decorated with CeO₂- and ZrO₂-based oxides, with special emphasis on metal–support interactions, reducibility, oxygen vacancies, hydrogen selectivity and the suppression of undesired methanation pathways.

This achievement represents an important milestone in Dr. Gasparetto’s scientific career and reflects the quality of the research developed in collaboration between UFSM and ITQ, CSIC-UPV.

The CATREDOX Group is very pleased to have contributed to this doctoral work and wishes Dr. Henrique Gasparetto continued success in the next stages of his scientific career.

The CATREDOX Group warmly congratulates Dr. Minjie Zhao on the successful defense of the doctoral thesis, which was awarded the distinction Cum Laude, the highest academic recognition for a PhD thesis.

The thesis, entitled “Investigation of alkenes hydroformylation and CO₂ hydrogenation on confined metal species”, was supervised by Prof. Avelino Corma Canós and Dr. Patricia Concepción Heydorn.

This achievement represents an important milestone in Dr. Zhao’s scientific career and reflects the quality, dedication and impact of the research developed during the doctoral period.

The CATREDOX Group is very proud of this accomplishment and wishes Dr. Minjie Zhao continued success in the next stages of the scientific career.

Abstract

The efficient conversion of CO2 into renewable CH4 continues to motivate the development of advanced methanation catalysts. In this work, CO2 hydrogenation was investigated over a ruthenium-based catalyst supported on yttria-doped ZrO2 (Ru/YSZ), reduced at 150, 250, and 500 °C. IR-CO spectroscopy and XPS analyses demonstrate that reduction temperature governs the local Ru environment, with interfacial and partially oxidized Ruδ+ species predominating at low reduction temperatures, resulting in enhanced catalytic performance. To overcome the common limitations of conventional kinetic analysis, an advanced data-reconciliation methodology using Markov Chain Monte Carlo (MCMC) simulations was implemented. The combination of spectroscopic studies and multiple reparameterizations with MCMC simulations identified direct CO2 dissociation as the preferred kinetic pathway, rather than the H-assisted formate mechanism on the 250 °C reduced Ru/YSZ sample, with apparent activation energies predicted to be 0.94 eV and 2.58 eV, respectively. Posterior parameter correlations further reveal a strong coupling between CO2 activation and active-site regeneration mediated by terminal water. 

Minjie Zhao, estudiante de doctorado del grupo CATREDOX defenderá su tesis doctoral “Investigation of alkenes hydroformylation and CO2 hydrogenation on confined metal species”.

Fecha: 20 de julio de 2026 (12:00h)

Lugar: Salón de Actos del ITQ (CSIC-UPV)

Dirección: Avelino Corma Canós y Patricia Concepción Heydorn

Programa de doctorado: Programa de Doctorado en Química Sostenible

The Instituto de Tecnología Química (ITQ, UPV-CSIC) recently hosted the Second Working and Collaboration Meeting of the project COOPB25065, funded under the CSIC I-COOP 2025 Programme from 8 to 11 June 2026,.

The meeting brought together researchers from the Universidad Nacional del Litoral and INTEC-CONICET in Argentina, the Instituto de Catálisis y Petroleoquímica (ICP-CSIC, Madrid), and the Instituto de Tecnología Química (ITQ, UPV-CSIC, Valencia). Participants included Prof. Sebastián Collins, Prof. María Verónica Ganduglia-Pirovano, Dr. Pablo Lustemberg, Dr. Daviel Gómez, and Dr. Patricia Concepción (project coordinator).

During the meeting, the consortium reviewed preliminary scientific results, discussed the complementary technological capabilities available at each institution, and defined future research activities aimed at maximizing the scientific impact of the collaboration.

This initiative highlights the importance of international cooperation in promoting scientific excellence, strengthening research capacities, and fostering long-term partnerships between institutions committed to addressing global scientific and technological challenges.

The CATREDOX Group thanks all participants for their commitment and looks forward to the next milestones of the project.

Abstract

This study reveals the presence of low-atomicity copper(I) oxo clusters strongly anchored to ZnO in commercial-type Cu/ZnO catalysts that, coexisting with metallic copper nanoparticles, play a critical role in CO2 hydrogenation. Their detection is challenging because metallic copper nanoparticles dominate the catalyst surface and these clusters appear in low amounts. Nevertheless, definitive evidence of their existence comes from the combination of in situ Raman spectroscopy, temperature-programmed CO surface reaction (TPSR-CO), time-resolved kinetic studies, and advance microscopy studies (STEM-XEDS and STEM-EELS). Catalytic studies combined with density functional theory (DFT) calculations demonstrate its critical role in methanol production and their size-dependent contribution to the total activity compared to traditional Cu-ZnO interfacial sites. According to DFT studies, CO2 adsorption is significantly more favorable on small Cu14O7 and Cu32O16 clusters than on extended Cu2O (111) (110) facets, metallic copper, or conventional metal-support interfacial sites. Moreover, the stabilization of carboxyl rather than formate-like intermediates follows a similar trend than the methanol production, being preferential on small Cu14O7 and Cu32O16 clusters, underlying a carboxyl-type intermediate path in methanol production. 

Abstract

This work presents a strategy to control not only the distance and proximity of active sites at the atomic or nanoscale but also the nature of sites in zeolite-based catalysts, promoting the coupling rate of surface intermediate species and accordingly the formation rate of dimethyl ether (DME) by a direct CO2 hydrogenation path. We use a one-pot synthesis strategy and a thermal-induced detachment process of framework elements, such as Ga3+ ions, to stabilize PdGa alloys and Ga+ sites in close proximity to Brønsted acid sites under reductive conditions. Using this strategy, a production of oxygenates of up to 42,864 gMeOH+DME·kgPd–1·h–1 at 45 bar, 260 °C, and WHSV = 15,000 mL·gcat–1·h–1, is obtained with 80% selectivity to oxygenated (19% methanol/61% DME), outperforming the most active Pd-based CO2 hydrogenation catalysts in the literature. Time-resolved kinetic studies, in situ X-ray adsorption, and in situ and operando IR offer strong proof of the key role of isolated Ga+ Lewis acid sites in close proximity to Brønsted acid sites in stabilizing monoformate intermediate species and facilitating the direct production of DME. Finally, this work highlights the key role of the zeolite in metal confinement, conferring excellent stability, oxidation resistance, hydrophilicity, and close proximity of active sites together with the stabilization of low-coordinated Lewis acid sites.