Andreas Jentys

A heterogeneous Cu(0) catalyst enables efficient three-component carboboration and alkyl halide borylation under mild conditions, providing structurally diverse heteroatom-containing alkylboronates with excellent functional-group tolerance.

Carbon capture and utilization play an important role by converting CO ₂ emissions to high value fuels and chemicals such as methanol. This work reports the modelling and simulation of the CCU to methanol using a bifunctional catalyst with amine sites for CO ₂ capture and Pt sites to catalyze the reduction of intermediates to methanol. The bifunctional material exhibited high CO ₂ capture capacity under post‐combustion conditions at 50°C–70°C and promising methanol formation under dynamic experiments of sequential CO ₂ capture and hydrogenation steps. CO ₂ sorption experiments using TGA were employed to extract kinetics for the CO ₂ capture. Steady‐state CO ₂ hydrogenation over the bifunctional material was used for the development of the hydrogenation kinetic model. The validation of the kinetic models coupled with a transient reactor model under dynamic conditions showed that the model can predict the transient formation of methanol. A parametric investigation under varying operation conditions highlighted the advantage of isothermal cycles at high temperature with respect to experimental time efficiency and maximized methanol formation rate compromised by the lower capture capacity. Further investigations in material development focusing on the facilitation of the methanol desorption from the pores would significantly improve the combined process and allow more time‐efficient screening protocols.

A one‐step method was developed to synthesize highly ordered, primary amine–functionalized two‐dimensional (2D) hexagonal mesoporous polymers, designed to enhance the density of catalytically active sites for CO ₂ capture and subsequent hydrogenation to methanol. Incorporation of Pt nanoparticles generates an ordered bifunctional (base/metal) mesoporous system, enabling efficient CO ₂ adsorption and optimal metal utilization for effective methanol synthesis from the captured CO ₂ at the amine–metal interface. Compared with silica‐based materials, ^[1,2] this novel polymer achieves a fourfold increase in methanol yield while maintaining 100% selectivity under mild reaction conditions.

Combining operando X‐ray absorption spectroscopy (XAS) and computational modelling shows unequivocally the distribution of active species in fresh and hydrothermally aged Cu‐CHA and Cu‐AEI zeolites during NH₃‐assisted selective catalytic reduction of NO_x. Four principal species co‐exist: (i) Cu^I cations coordinated to NH₃, (ii) Cu^I cations coordinated to the zeolite framework, (iii) solvated Cu^II cations, and (iv) framework‐coordinated Cu^II species (Cu^II_st) formed upon hydrothermal ageing of the zeolite sample. The Cu^II_st species were only observed in the hydrothermally aged zeolite samples and are formed upon the interaction of hydrated Cu^II cations with extra‐framework Al (EFAl) generated during the hydrothermal treatment. These sites are inactive for NO_x reduction, leading to a decrease in the catalytic performance of the hydrothermally aged zeolites. Cu^II_st formation was higher in Cu‐CHA (~46 %) than in Cu‐AEI (~28 %). The better hydrothermal stability of Cu in the AEI framework is attributed to the tortuous channel structure of AEI that hinders the migration of hydrated Cu^II cations during hydrothermal ageing.

Combining operando X‐ray absorption spectroscopy (XAS) and computational modelling shows unequivocally the distribution of active species in fresh and hydrothermally aged Cu‐CHA and Cu‐AEI zeolites during NH₃‐assisted selective catalytic reduction of NO_x. Four principal species co‐exist: (i) Cu^I cations coordinated to NH₃, (ii) Cu^I cations coordinated to the zeolite framework, (iii) solvated Cu^II cations, and (iv) framework‐coordinated Cu^II species (Cu^II_st) formed upon hydrothermal ageing of the zeolite sample. The Cu^II_st species were only observed in the hydrothermally aged zeolite samples and are formed upon the interaction of hydrated Cu^II cations with extra‐framework Al (EFAl) generated during the hydrothermal treatment. These sites are inactive for NO_x reduction, leading to a decrease in the catalytic performance of the hydrothermally aged zeolites. Cu^II_st formation was higher in Cu‐CHA (~46 %) than in Cu‐AEI (~28 %). The better hydrothermal stability of Cu in the AEI framework is attributed to the tortuous channel structure of AEI that hinders the migration of hydrated Cu^II cations during hydrothermal ageing.

Die Entwicklung von multifunktionalen Materialien, die die Hell‐Dunkel‐Entkopplung der natürlichen Photosynthese nachahmen, ist eine zentrale Herausforderung im Bereich der Energieumwandlung. In diesem Artikel stellen wir MnBr‐253 vor, eine edelmetallfreie metall‐organische Gerüstverbindung (MOF), die aus Al‐Metallknotenpunkten, Bipyridin Linkern und MnBr(CO)₃(Bipyridin)‐Komplexen aufgebaut ist. Bei Bestrahlung zeigen die MnBr‐253 Kolloide eine Elektronen‐Photoladekapazität von ~42 C ⋅ g⁻¹_MOF, mit kompetetiver Photoladerate (1.28 C ⋅ s⁻¹ ⋅ g⁻¹_MOF) und einer Umwandlungseffizienz von einfallenden Photonen in Elektronen von ~9,4 % bei 450 nm. Spektroskopische und rechnerische Studien belegen eine effektive Elektronenakkumulation an dem Mn‐Komplex, während die hohe Porosität und Mn‐Beladung die bemerkenswerte Elektronenspeicherleistung erklären. Die geladenen MnBr‐253‐Pulver wurden erfolgreich für die Wasserstoffproduktion unter dunklen Bedingungen eingesetzt und damit die vom Licht entkoppelte Reaktivität der Photosynthese nachgeahmt.

Designing multifunctional materials that mimic the light‐dark decoupling of natural photosynthesis is a key challenge in the field of energy conversion. Herein, we introduce MnBr‐253, a precious metal‐free metal–organic framework (MOF) built on Al nodes, bipyridine linkers and MnBr(CO)₃(bipyridine) complexes. Upon irradiation, MnBr‐253 colloids demonstrate an electron photocharging capacity of ~42 C ⋅ g⁻¹_MOF, with state‐of‐the‐art photocharging rate (1.28 C ⋅ s⁻¹ ⋅ g⁻¹_MOF) and incident photon‐to‐electron conversion efficiency of ~9.4 % at 450 nm. Spectroscopic and computational studies support effective electron accumulation at the Mn complex while high porosity and Mn loading account for the notable electron storage performance. The charged MnBr‐253 powders were successfully applied for hydrogen evolution under dark conditions thus emulating the light‐decoupled reactivity of photosynthesis.

Bifunctional basic‐metallic catalysts proved to be efficient for the selective hydrogenation of CO₂ to methanol. The activity of these catalysts depends on the cooperative interaction between the amine groups and metallic sites, which is a function of amine group density, Pd particle perimeter length and the geometric properties of support pores. The pore width has the highest effect on the activity, increasing the methanol yield by about half an order of magnitude. Confining the space leads to a three‐dimensional utilization of the available metal surface sites compared to a two‐dimensional distribution of the bifunctional sites in larger pores, where the metal particle diameter is the decisive factor for the catalytic properties.