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Direct hydrogen peroxide (H 2 O 2 ) electrosynthesis via the two-electron oxygen reduction reaction is a sustainable alternative to the traditional energy-intensive anthraquinone technology. However, high-performance and scalable electrocatalysts with industrial-relevant production rates remain to be challenging, partially due to insufficient atomic level understanding in catalyst design. Here we utilize theoretical approaches to identify transition-metal single-site catalysts for two-electron oxygen reduction using the *OOH binding energy as a descriptor. The theoretical predictions are then used as guidance to synthesize the desired cobalt single-site catalyst with a O-modified Co-(pyrrolic N) 4 configuration that can achieve industrial-relevant current densities up to 300 mA cm − 2 with 96–100% Faradaic efficiencies for H 2 O 2 production at a record rate of 11,527 mmol h − 1  g cat − 1 . Here, we show the feasibility and versatility of metal single-site catalyst design using various commercial carbon and cobalt phthalocyanine as starting materials and the high applicability for H 2 O 2 electrosynthesis in acidic, neutral and alkaline electrolytes. Direct hydrogen peroxide electrosynthesis offers a sustainable alternative to the traditional energy-intensive anthraquinone technology. Here, the authors report a scalable cobalt single-site catalyst for hydrogen peroxide synthesis at industrial-relevant currents in acidic, neutral or alkaline electrolyte.

The synergistic interaction among different components in complex catalysts is one of the crucial factors in determining catalytic performance. Here we report the interactions among the three components in controlling the catalytic performance of Cu–ZnO–ZrO 2 (CZZ) catalyst for CO 2 hydrogenation to methanol. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) measurements under the activity test pressure (3 MPa) reveal that the CO 2 hydrogenation to methanol on the CZZ catalysts follows the formate pathway. Density functional theory (DFT) calculations agree with the in situ DRIFTS measurements, showing that the ZnO–ZrO 2 interfaces are the active sites for CO 2 adsorption and conversion, while the presence of metallic Cu is also necessary to facilitate H 2 dissociation and to provide hydrogen resource. The combined experiment and DFT results reveal that tuning the interaction between ZnO and ZrO 2 can be considered as another important factor for designing high performance catalysts for methanol generation from CO 2 . Despite great efforts, the reaction mechanism of CO 2 hydrogenation to methanol and the nature of the active sites on Cu–ZnO–ZrO 2 (CZZ) catalysts are still under debate. Herein, the authors report the interactions among the three components in controlling the catalytic performance of CZZ catalyst for CO 2 hydrogenation to methanol.

Designing highly active and stable catalytic sites is often challenging due to the complex synthesis procedure and the agglomeration of active sites during high-temperature reactions. Here, we report a facile two-step method to synthesize Pt clusters confined by In-modified ZSM-5 zeolite. In-situ characterization confirms that In is located at the extra-framework position of ZSM-5 as In + , and the Pt clusters are stabilized by the In-ZSM-5 zeolite. The resulting Pt clusters confined in In-ZSM-5 show excellent propane conversion, propylene selectivity, and catalytic stability, outperforming monometallic Pt, In, and bimetallic PtIn alloys. The incorporation of In + in ZSM-5 neutralizes Brønsted acid sites to inhibit side reactions, as well as tunes the electronic properties of Pt clusters to facilitate propane activation and propylene desorption. The strategy of combining precious metal clusters with metal cation-exchanged zeolites opens the avenue to develop stable heterogeneous catalysts for other reaction systems. Designing highly active and stable catalytic sites is often challenging due to complex synthesis procedures and the agglomeration of active sites during high-temperature reactions. Here the authors present a two-step method to synthesize Pt clusters in In-modified ZSM-5, resulting in superior propane dehydrogenation performance.

Efficient electroreduction of CO 2 to multi-carbon products is a challenging reaction because of the high energy barriers for CO 2 activation and C–C coupling, which can be tuned by designing the metal centers and coordination environments of catalysts. Here, we design single atom copper encapsulated on N-doped porous carbon (Cu-SA/NPC) catalysts for reducing CO 2 to multi-carbon products. Acetone is identified as the major product with a Faradaic efficiency of 36.7% and a production rate of 336.1 μg h −1 . Density functional theory (DFT) calculations reveal that the coordination of Cu with four pyrrole-N atoms is the main active site and reduces the reaction free energies required for CO 2 activation and C–C coupling. The energetically favorable pathways for CH 3 COCH 3 production from CO 2 reduction are proposed and the origin of selective acetone formation on Cu-SA/NPC is clarified. This work provides insight into the rational design of efficient electrocatalysts for reducing CO 2 to multi-carbon products. Efficient electroreduction of CO 2 to multi-carbon products is challenging. Here, the single atom Cu encapsulated on N-doped porous carbon catalysts are designed for reducing CO 2 to acetone at low overpotentials and the active sites are identified as Cu coordination with four pyrrole-N atoms.

Many research efforts into CO 2 reduction to valuable products are motivated by a desire to reduce the atmospheric CO 2 concentration. However, it is unclear how laboratory-scale catalytic performance translates to the goal of reducing CO 2 . In this Perspective, we analyse recently reported thermocatalytic and electrocatalytic performances for reduction of CO 2 to methanol in terms of net CO 2 reduction, on a mole basis. Our calculations indicate that even an ideal catalytic process needs to be powered by electricity emitting less than 0.2 kg of CO 2 per kWh to achieve a net reduction in CO 2 . We conclude that hybrid processes combining thermocatalysis and electrocatalysis are promising opportunities to reduce CO 2 to methanol, as long as practical electrocatalysts achieve reaction rates two orders of magnitude larger than those observed in current laboratory tests. In such a scenario, an increase in the global methanol market could benefit the overall reduction of atmospheric CO 2 via conversion of CO 2 to methanol. CO 2 hydrogenation is frequently acclaimed as a strategy for greenhouse gases mitigation, although the carbon footprint of the corresponding electrocatalytic or thermocatalytic process is often neglected. This Perspective analyses the amount of CO 2 generated during methanol production for different catalytic processes and hybrid thereof.

Electrochemical synthesis of H 2 O 2 through a selective two-electron (2e − ) oxygen reduction reaction (ORR) is an attractive alternative to the industrial anthraquinone oxidation method, as it allows decentralized H 2 O 2 production. Herein, we report that the synergistic interaction between partially oxidized palladium (Pd δ+ ) and oxygen-functionalized carbon can promote 2e − ORR in acidic electrolytes. An electrocatalyst synthesized by solution deposition of amorphous Pd δ+ clusters (Pd 3 δ+ and Pd 4 δ+ ) onto mildly oxidized carbon nanotubes (Pd δ+ -OCNT) shows nearly 100% selectivity toward H 2 O 2 and a positive shift of ORR onset potential by ~320 mV compared with the OCNT substrate. A high mass activity (1.946 A mg −1 at 0.45 V) of Pd δ+ -OCNT is achieved. Extended X-ray absorption fine structure characterization and density functional theory calculations suggest that the interaction between Pd clusters and the nearby oxygen-containing functional groups is key for the high selectivity and activity for 2e − ORR. Electrocatalysts which deliver high selectivity for two-electron oxygen reduction to hydrogen peroxide in acidic media are sought to replace the conventional anthraquinone process. Here, the authors develop partially oxidised palladium clusters on carbon nanotubes with near 100% selectivity.

The inherent variability and insufficiencies in the co-production of propylene from steam crackers has raised concerns regarding the global propylene production gap and has directed industry to develop more on-purpose propylene technologies. The oxidative dehydrogenation of propane by CO 2 (CO 2 -ODHP) can potentially fill this gap while consuming a greenhouse gas. Non-precious FeNi and precious NiPt catalysts supported on CeO 2 have been identified as promising catalysts for CO 2 -ODHP and dry reforming, respectively, in flow reactor studies conducted at 823 K. In-situ X-ray absorption spectroscopy measurements revealed the oxidation states of metals under reaction conditions and density functional theory calculations were utilized to identify the most favorable reaction pathways over the two types of catalysts. The oxidative dehydrogenation of propane by CO 2 (CO 2 -ODHP) can potentially fill the gap of propylene production while consuming a greenhouse gas. Here, the authors identify non-precious FeNi and precious NiPt catalysts supported on CeO 2 as promising catalysts for CO 2 -ODHP and dry reforming, respectively, in flow reactor studies.

The electrochemical carbon dioxide reduction reaction to syngas with controlled CO/H 2 ratios has been studied on Pd-based bimetallic hydrides using a combination of in situ characterization and density functional theory calculations. When compared with pure Pd hydride, the bimetallic Pd hydride formation occurs at more negative potentials for Pd-Ag, Pd-Cu, and Pd-Ni. Theoretical calculations show that the choice of the second metal has a more significant effect on the adsorption strength of *H than *HOCO, with the free energies between these two key intermediates (i.e., ΔG(*H)–ΔG(*HOCO)) correlating well with the carbon dioxide reduction reaction activity and selectivity observed in the experiments, and thus can be used as a descriptor to search for other bimetallic catalysts. The results also demonstrate the possibility of alloying Pd with non-precious transition metals to promote the electrochemical conversion of CO 2 to syngas. Converting solar energy to hydrogen fuel requires light-absorbers that well-match the wavelengths of incoming sunlight. Here, authors prepare a broadband visible-light-absorbing molecular complex that efficiently produces hydrogen from water.

Harnessing renewable electricity to drive the electrochemical reduction of CO 2 is being intensely studied for sustainable fuel production and as a means for energy storage. Copper is the only monometallic electrocatalyst capable of converting CO 2 to value-added products, e.g., hydrocarbons and oxygenates, but suffers from poor selectivity and mediocre activity. Multiple oxidative treatments have shown improvements in the performance of copper catalysts. However, the fundamental underpinning for such enhancement remains controversial. Here, we combine reactivity, in-situ surface-enhanced Raman spectroscopy, and computational investigations to demonstrate that the presence of surface hydroxyl species by co-electrolysis of CO 2 with low concentrations of O 2 can dramatically enhance the activity of copper catalyzed CO 2 electroreduction. Our results indicate that co-electrolysis of CO 2 with an oxidant is a promising strategy to introduce catalytically active species in electrocatalysis. While the electrochemical conversion of CO 2 to highly reduced products is unique to copper, there are still gaps in understanding copper catalysts’ efficacy. Here, authors find that co-electrolysis of CO 2 with O 2 can enhance copper’s catalytic activities.

How much carbon does it take to make nitric acid? The counterintuitive answer nowadays is quite a lot. Nitric acid is manufactured by ammonia oxidation, and all the hydrogen to make ammonia via the Haber-Bosch process comes from methane. That's without even accounting for the fossil fuels burned to power the process. Chen et al. review research prospects for more sustainable routes to nitrogen commodity chemicals, considering developments in enzymatic, homogeneous, and heterogeneous catalysis, as well as electrochemical, photochemical, and plasma-based approaches. Science , this issue p. eaar6611 Nitrogen is fundamental to all of life and many industrial processes. The interchange of nitrogen oxidation states in the industrial production of ammonia, nitric acid, and other commodity chemicals is largely powered by fossil fuels. A key goal of contemporary research in the field of nitrogen chemistry is to minimize the use of fossil fuels by developing more efficient heterogeneous, homogeneous, photo-, and electrocatalytic processes or by adapting the enzymatic processes underlying the natural nitrogen cycle. These approaches, as well as the challenges involved, are discussed in this Review.