Speciation and Reactivity Control of Cu-Oxo Clusters via Extraframework Al in Mordenite for Methane Oxidation

The stoichiometric conversion of methane to methanol by Cu-exchanged zeolites can be brought to highest yields by the presence of extraframework Al and high CH₄ chemical potentials. Combining theory and experiments, the differences in chemical reactivity of monometallic Cu-oxo and bimetallic Cu-Al-oxo nanoclusters stabilized in...

Mapping the reaction landscape for the C1 chemistry

In this thesis, we have presented and investigated the possible strategies for modelling complex heterogeneous catalytic systems in operando regimes. By introducing modern computational approaches to sample the potential energy surface of the catalytic active site, we have attempted to account for the reactive conditions, solvent presence,...

Solvent-mediated outer-sphere CO2 electro-reduction mechanism over the Ag111 surface

The electrocatalytic CO2 reduction reaction (CO2RR) is one of the key technologies of the clean energy economy. Molecular-level understanding of the CO2RR process is instrumental for the better design of electrodes operable at low overpotentials with high current density. The catalytic mechanism underlying the turnover and selectivity of the...

High Stability of Methanol to Aromatic Conversion over Bimetallic Ca,Ga-Modified ZSM-5

The production of valuable aromatics and the rapid catalyst deactivation due to coking are intimately related in the zeolite-catalyzed aromatization reactions. Here, we demonstrate that these two processes can be decoupled by promoting the Ga/HZSM-5 aromatization catalyst with Ca. The resulting bimetallic catalysts combine high selectivity to...

Global optimization of extraframework ensembles in zeolites: structural analysis of extraframework aluminum species in MOR and MFI zeolites

Metal-modified zeolites are versatile catalytic materials with a wide range of industrial applications. Their catalytic behaviour is determined by the nature of externally introduced cationic species, i.e., its geometry, chemical composition, and location within the zeolite pores. Superior catalyst designs can be unlocked by understanding the...

Unraveling the Nature of Extraframework Catalytic Ensembles in Zeolites: Flexibility and Dynamics of the Copper-Oxo Trimers in Mordenite

Extraframework cations define the chemical versatility of zeolite catalysts. Addressing their structural complexity and dynamic behavior represents one of the main fundamental challenges in the field. Herein, we present a computational approach for the identification and analysis of the accessible pool of intrazeolite extraframework complexes...

Importance of Methane Chemical Potential for Its Conversion to Methanol on Cu-Exchanged Mordenite

Copper-oxo clusters exchanged in zeolite mordenite are active in the stoichiometric conversion of methane to methanol at low temperatures. Here, we show an unprecedented methanol yield per Cu of 0.6, with a 90–95 % selectivity, on a MOR solely containing [Cu₃(μ-O)₃]²⁺ active sites. DFT calculations,...

Inkjet printing of Sc-Doped TiO₂ with enhanced photoactivity

Here we report the methodology for nanocomposite fabrication based on the inkjet printing technique. Doped TiO₂ nanoparticles with Sc contents up to 10 wt.% were synthesized and adapted towards a facile fabrication of microscale structures and thin film printing. Implementation of the state-of-the-art low-temperature synthesis...

Breaking Linear Scaling Relationships with Secondary Interactions in Confined Space: A Case Study of Methane Oxidation by Fe/ZSM-5 Zeolite

Linear energy scaling laws connect the kinetic and thermodynamic parameters of key elementary steps for heterogeneously catalyzed reactions over defined active sites on open surfaces. Such scaling laws provide a framework for a rapid computational activity screening of families of catalysts, but they also effectively impose a fundamental...

Degradation paths of manganese-based MOF materials in a model oxidative environment: a computational study

Stability is the key property of functional materials. In this work we investigate computationally the degradative potential of a model Mn-BTC (BTC = benzene-1,3,5-tricarboxylate) metal–organic framework (MOF) building block in aqueous solutions under oxidative conditions. Model density functional theory calculations have shown that the direct...

Efficient extraction of multivalent cations from aqueous solutions into sitinakite-based sorbents

A highly selective adsorbent for multivalent cationic species based on a sitinakite-type titanosilicate was prepared from a leucoxene ore enrichment waste. The synthesized material was used as for the selective removal of alkali-earth strontium (II) and barium (II) cations as well as for the cationic species based on the natural isotopes of...

Response to Comment “On the Existence of Excitonic Signatures in the Optical Response of Metal–Organic Frameworks”

This is a response to a comment on the interpretation of the origin of the nonlinear changes of optical properties of van der Waals' metal–organic frameworks (MOFs). The concerns are addressed by clarifying potential pitfalls in density functional theory (DFT) simulations, careful analysis of prior literature, and additionally discussing the...