The nickel-containing carbon monoxide dehydrogenase (CODH) uses a unique heterometallic [NiFe4S4] cluster active site, called the C-cluster, to catalyze the reversible reduction of carbon dioxide (CO2...

Electrochemical CO2 reduction (CO2RR) offers a promising strategy to recycle carbon by converting CO2 into valuable fuels and chemicals. So far, Cu-based catalysts remain the most effective for produc...

Nonoxidative coupling of methane represents a long-standing challenge in heterogeneous catalysis, as it requires activation of the carbon–hydrogen (C–H) bond, controlled carbon–carbon (C–C) bond formation, and effective hydrogen management without relying on oxidants. Here, we report a low-temperature C–H activation and nonoxidative C–C coupling of methane over atomically dispersed titanium–aluminum–boron nanopowder (Ti–Al–B NP) utilizing a catalytic microreactor coupled to synchrotron single-photon photoionization reflectron time-of-flight mass spectrometry. The soft-ionization, in situ probing method detects the nascent reaction products and radical intermediates under operando conditions, including methyl radical, C2 hydrocarbons, and molecular hydrogen. Methane activation is initiated at 800 K, approximately 700 K below the gas-phase decomposition threshold, leading predominantly to ethylene formation with selectivity reaching up to 78% among the C–C coupled products. Electronic structure calculations on model Ti–Al–B clusters elucidate a cooperative catalytic mechanism in which titanium enables methane adsorption and C–H activation, boron acts as a reversible hydrogen reservoir, and aluminum stabilizes methylene intermediates, thereby facilitating selective C–C coupling and dehydrogenation. These findings establish a distinct catalyst architecture for nonoxidative methane coupling based on earth abundant elements alternative to expensive platinum and other noble metal-containing conventional catalysts and provide molecular-level design principles for controlling dehydrogenation and subsequent C–C bond formation in challenging light alkane conversions.

Direct conversion of captured forms of carbon, or reactive carbon capture (RCC), presents an opportunity to reduce the energy intensity and cost of direct CO2 utilization from dilute sources. While amine-based sorbents effectively capture CO2, their use for RCC presents numerous challenges with typical pure metal catalysts used for electrochemical CO2 reduction (CO2R). Here, using both theory and experiments, we find that Ni–N–C single atom catalysts are effective for RCC conversion to CO using a diethanolamine sorbent, in contrast to pure metal catalysts. Computational analysis reveals that RCC can proceed directly through direct reduction of the sorbent-CO2 adduct or indirectly by C–N bond breaking facilitating CO2 adsorption and subsequent reduction. We find that the latter mechanism is most prevalent at low overpotentials where we experimentally observe RCC selectivity. We also find experimentally that the rate of CO production for RCC with Ni–N–C catalysts can exceed pure bicarbonate solutions at intermediate sorbent concentration (0.1–0.5 M DEA) under dilute (10–25%) streams of CO2 at low overpotentials. The coordination environment of Ni sites and the solution speciation influence their RCC activity, with changes in protonation to coordinating N/C atoms resulting in changing the RCC mechanism and consequent activity. In situ X-ray absorption spectroscopy and computational analysis reveal restructuring under RCC conditions due to hydrogen coadsorption with DEA that limits the stability of Ni–N–C catalysts. This work highlights the importance of carefully controlling the catalyst and solution environment to achieve active and stable RCC electrocatalysis.

We report detailed characterization of the vibronic interactions between the first two electronically excited states, Ã and B̃, in SrOPh (Ph = phenyl, –C6H5) a

Mass-selected Ptn+ (n ≤ 7) were deposited at variable energies on highly oriented pyrolytic graphite (HOPG), creating highly active hydrogen evolution reaction (HER) electrocatalysts. HER mass activit...

The nanoscale structure of electrocatalyst surfaces governs the selectivity and kinetics of reactions including CO(2) electroreduction (CO(2)R). Yet, their evolution under reaction conditions remains elusive, and the roles of surface hydroxyls (OHad) and the interfacial microenvironment in surface restructuring are poorly understood. Combining electrochemical atomic force microscopy, Raman spectroscopy, and grand canonical modeling, we reveal that OHad acts synergistically with COad to restructure copper (Cu) electrocatalysts during COR. Mixed OHad/COad coverage promotes lifting of surface atoms into metastable states, generating Cu adatoms and nanoclusters at mild cathodic potentials, which aggregate or dissolve at more negative potentials. This restructuring into low-coordinated Cu sites is accompanied by disordering of the interfacial water network. Nanocluster stability depends critically on CO partial pressure, while hydroxyls remain kinetically trapped on the roughened Cu surface. These findings underscore the importance of surface kinetics and interfacial microenvironments in atomic-scale surface restructuring, urging a reassessment of catalytic surface states under realistic conditions.

The dynamic restructuring of Cu surfaces under electrochemical CO2 reduction conditions is crucial for determining their catalytic performance, particularly for multicarbon products such as ethylene a...

The nanoscale structure of electrocatalyst surfaces governs the selectivity and kinetics of reactions including CO(2) electroreduction (CO(2)R). Yet, their evolution under reaction conditions remains elusive, and the roles of surface hydroxyls (OHad) and the interfacial microenvironment in surface restructuring are poorly understood. Combining electrochemical atomic force microscopy, Raman spectroscopy, and grand canonical modeling, we reveal that OHad acts synergistically with COad to restructure copper (Cu) electrocatalysts during COR. Mixed OHad/COad coverage promotes lifting of surface atoms into metastable states, generating Cu adatoms and nanoclusters at mild cathodic potentials, which aggregate or dissolve at more negative potentials. This restructuring into low-coordinated Cu sites is accompanied by disordering of the interfacial water network. Nanocluster stability depends critically on CO partial pressure, while hydroxyls remain kinetically trapped on the roughened Cu surface. These findings underscore the importance of surface kinetics and interfacial microenvironments in atomic-scale surface restructuring, urging a reassessment of catalytic surface states under realistic conditions.

Here we evaluate the robustness and utility of quantum mechanical descriptors for machine learning with transition metal complexes. We utilize ab initio information from the quantum theory of atoms-in...

Understanding and designing active sites in single-atom catalysts (SACs) requires going beyond static models to capture their dynamic evolution under realistic electrochemical conditions. Here, we dev...

Nature Chemistry - Alkaline-earth phenoxides show promise as optical cycling centres; however, their properties when connected to larger structures is unclear. Now it has been shown that their...

Susumu Kitagawa, Richard Robson and Omar M. Yaghi win the prize for developing metal–organic frameworks