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Amino acids are the building blocks of proteins and are widely used as important ingredients for other nitrogen‐containing molecules. Here, we report the sustainable production of amino acids from biomass‐derived hydroxy acids with high activity under visible‐light irradiation and mild conditions, using atomic ruthenium‐promoted cadmium sulfide (Ru1/CdS). On a metal basis, the optimized Ru1/CdS exhibits a maximal alanine formation rate of 26.0 molAla ⋅ gRu−1 ⋅ h−1, which is 1.7 times and more than two orders of magnitude higher than that of its nanoparticle counterpart and the conventional thermocatalytic process, respectively. Integrated spectroscopic analysis and density functional theory calculations attribute the high performance of Ru1/CdS to the facilitated charge separation and O−H bond dissociation of the α‐hydroxy group, here of lactic acid. The operando nuclear magnetic resonance further infers a unique "double activation" mechanism of both the CH−OH and CH3−CH−OH structures in lactic acid, which significantly accelerates its photocatalytic amination toward alanine. [ABSTRACT FROM AUTHOR]

Amino acids are the building blocks of proteins and are widely used as important ingredients for other nitrogen‐containing molecules. Here, we report the sustainable production of amino acids from biomass‐derived hydroxy acids with high activity under visible‐light irradiation and mild conditions, using atomic ruthenium‐promoted cadmium sulfide (Ru1/CdS). On a metal basis, the optimized Ru1/CdS exhibits a maximal alanine formation rate of 26.0 molAla ⋅ gRu−1 ⋅ h−1, which is 1.7 times and more than two orders of magnitude higher than that of its nanoparticle counterpart and the conventional thermocatalytic process, respectively. Integrated spectroscopic analysis and density functional theory calculations attribute the high performance of Ru1/CdS to the facilitated charge separation and O−H bond dissociation of the α‐hydroxy group, here of lactic acid. The operando nuclear magnetic resonance further infers a unique "double activation" mechanism of both the CH−OH and CH3−CH−OH structures in lactic acid, which significantly accelerates its photocatalytic amination toward alanine. [ABSTRACT FROM AUTHOR]

The optimal ratio of reaction solutions resulted in excellent performance and product selectivity of CuO/g-C3N4 composites in the photocatalytic CO2 reduction reaction. A pH-dependent chemical exchange saturation transfer (CEST) imaging nuclear magnetic resonance (NMR) method was used to confirm that CuO modification improves the adsorption capacity of CO2. [ABSTRACT FROM AUTHOR]

Engineering surface-active facets of metal cocatalysts is one of the most widely explored strategies to develop advanced photocatalysts and promote photocatalytic solar energy conversion. Here, the surface-active facets of Pd nanocrystals in Pd/g-C 3 N 4 photocatalyst was related to the injection flow rate of PdCl 2. When PdCl 2 was injected at a low flow rate of 7.5 mL/h (7.5-Pd/g-C 3 N 4), the Pd nanocrystals were uniformly dispersed onto the g-C 3 N 4 with exposed low-index {100} and {111} surface-active facets. However, increasing the injection flow rate to 150 mL/h (150-Pd/g-C 3 N 4) formed Pd nanocrystals where only the {100} surface-active facet was exposed. Under visible light irradiation, the 7.5-Pd/g-C 3 N 4 nanocomposite exhibited excellent water splitting activity for hydrogen production (7.61 mmol g−1 h−1), which was significantly better than with the 150-Pd/g-C 3 N 4 nanocomposite (3.3 mmol g−1 h−1). Theoretical calculations and experimental results confirm the importance of the {111} surface-active facets in the 7.5-Pd/g-C 3 N 4 nanocomposite for promoting photocatalytic activity. [Display omitted] • The Pd/g-C 3 N 4 photocatalyst was prepared in a simple one-pot synthesis method. • The surface-active facets of Pd nanocrystals in Pd/g-C 3 N 4 was controlled by the injection flow rate of PdCl 2. • 7.5-Pd/g-C 3 N 4 nanocomposite exhibited excellent photocatalytic activity for H 2 production. • 7.5-Pd/g-C 3 N 4 nanocomposite also shown good performance in varied photocatalytic reactions. [ABSTRACT FROM AUTHOR]

The construction of efficient and stable non-noble metal bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) presents a challenge in electrocatalytic water splitting. CoS 2 is a promising electrocatalyst that could replace precious metals. In this work, a series of Co-MOF precursors having average particle sizes ranging from the nanometer to the micron scale (86–1084 nm) were synthesized in an unprecedented attempt; Co/CoS 2 heterojunction embedded in nitrogen doped carbon framework (Co/CoS 2 @NC) was prepared through further carbonization and sulfurization. The samples were characterized and evaluated by X-ray powder diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and electrochemical techniques. The results indicate that when the size of Co-MOF is less than 300 nm, the cubic structure framework easily collapses to form the spherical structure during the carbonization process. The catalytic activity of Co@NC is size-dependent; Co/CoS 2 @NC exhibited the best performance among the series, with an overpotential of 188 mV for HER and 349 mV for OER at a current density of 10 mA cm−2. This work provides experimental guidance for the design and synthesis of low-cost, efficient, and robust Co-based electrocatalysts. • With Co-MOF cubic nanoparticles as the precursor, Co/CoS 2 @NC was prepared through carbonization and sulfurization. • Co/CoS 2 @NC exhibited the best performance among the series. • The catalytic activity of Co@NC is size-dependent. • This work provides a guidance for the design and synthesis of low-cost, efficient, and robust Co-based electrocatalysts. [ABSTRACT FROM AUTHOR]

Solar‐driven transfer hydrogenation of unsaturated bonds has received considerable attention in the research area of sustainable organic synthesis; however, water, the ultimate green source of hydrogen, has rarely been investigated due to the high barrier associated with splitting of water molecules. We report a carbon‐nitride‐supported palladium single‐atom heterogeneous catalyst with unparalleled performance in photocatalytic water‐donating transfer hydrogenation compared to its nanoparticle counterparts. Isotopic‐labeling experiments and operando nuclear magnetic resonance measurements confirm the direct hydrogenation mechanism using in situ‐generated protons from water splitting under visible‐light irradiation. Density functional theory calculations attribute the high activity to lower barriers for hydrogenation, facilitated desorption of ethylbenzene, and facile hydrogen replenishment from water on the atomic palladium sites. [ABSTRACT FROM AUTHOR]

Solar‐driven transfer hydrogenation of unsaturated bonds has received considerable attention in the research area of sustainable organic synthesis; however, water, the ultimate green source of hydrogen, has rarely been investigated due to the high barrier associated with splitting of water molecules. We report a carbon‐nitride‐supported palladium single‐atom heterogeneous catalyst with unparalleled performance in photocatalytic water‐donating transfer hydrogenation compared to its nanoparticle counterparts. Isotopic‐labeling experiments and operando nuclear magnetic resonance measurements confirm the direct hydrogenation mechanism using in situ‐generated protons from water splitting under visible‐light irradiation. Density functional theory calculations attribute the high activity to lower barriers for hydrogenation, facilitated desorption of ethylbenzene, and facile hydrogen replenishment from water on the atomic palladium sites. [ABSTRACT FROM AUTHOR]

[Display omitted] • Operando NMR combined with gas-probe method was used to study active sites transfer under the metal-support interaction. • The photocatalytic conversion efficiency of pure TiO 2 decreased, while that of Pt/TiO 2 was unaffected in gas conditions. • After loading metal-Pt, active sites changed from TiO 2 surface to Pt/TiO 2 interface. Recently metal-support interaction (MSI) has attracted considerable attention in photocatalysis. Some studies emphasize the importance of active sites on photocatalysts; however, there are no reports on site changes under MSI in real reactive conditions. Herein, an operando nuclear magnetic resonance technique was proposed to study such site changes on anatase TiO 2 and Pt/TiO 2 , through a gas-probe method, in CH 3 OH reforming. The photocatalytic oxidation efficiency of CH 3 OH by pure TiO 2 decreased immensely under extra-gas conditions, while that by Pt/TiO 2 was unaffected. The surface of pure TiO 2 were occupied by injected gas molecules, making CH 3 OH inaccessible to active sites. However, in Pt/TiO 2 , CH 3 OH adsorption sites changed from TiO 2 surface to metal-Pt/TiO 2 interface as confirmed by H 2 gas-probe experiments. This study provides a deeper understanding of active sites transfer by MSI and leverages the gas-probe method for its detection to guide the development of technology to test active-site positions in heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

Nano-structuring and metal-support interactions are effective methods to improve the electrocatalytic activity of heterogeneous catalysis. In this study, we synthesized nitrogen-doped porous carbon substrates by using a SiO 2 -protected calcination strategy with ZIF-8 as a precursor. The experimental results revealed the prepared porous nitrogen-doped carbon (PNC) to have high dispersion, large specific surface area, and rich pore structure, allowing high exposure of active sites. The carbon support showed optimum characteristics to deposit precious metals with small particle sizes. X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) showed that the N groups on the PNC substrates served as coordination sites for Ru, allowing the formation of ultrafine nanoclusters. The Ru clusters showed good metal dispersion, exposing more active sites and improving the utilization of the precious metal. At a current density of 10 mA/cm2, Ru/PNC showed a minimum overpotential of 40 mV. This work provided a simple and effective method for the preparation of excellent carbon substrates and the synthesis of metal clusters with small particle sizes. N-doped porous carbon (PNC) was synthesized by a SiO 2 -protected calcination strategy by using ZIF-8 as precursor. Compared with Ru/NC, the HER catalytic performance of Ru/PNC catalysts with Ru clusters has been significantly improved. [Display omitted] • Ru nanoclusters was prepared by the EG microwave-assisted method. • N-doped porous carbon was synthesized by a SiO 2 -protected calcination strategy. • Ru/PNC catalyst showed excellent HER-catalytic performance in acidic media. [ABSTRACT FROM AUTHOR]

Copper‐based materials are efficient electrocatalysts for the conversion of CO2 to C2+ products, and most these materials are reconstructed in situ to regenerate active species. It is a challenge to precisely design precatalysts to obtain active sites for the CO2 reduction reaction (CO2RR). Herein, we develop a strategy based on local sulfur doping of a Cu‐based metal–organic framework precatalyst, in which the stable Cu−S motif is dispersed in the framework of HKUST‐1 (S‐HKUST‐1). The precatalyst exhibits a high ethylene selectivity in an H‐type cell with a maximum faradaic efficiency (FE) of 60.0 %, and delivers a current density of 400 mA cm−2 with an ethylene FE up to 57.2 % in a flow cell. Operando X‐ray absorption results demonstrate that Cuδ+ species stabilized by the Cu−S motif exist in S‐HKUST‐1 during CO2RR. Density functional theory calculations indicate the partially oxidized Cuδ+ at the Cu/CuxSy interface is favorable for coupling of the *CO intermediate due to the modest distance between coupling sites and optimized adsorption energy. [ABSTRACT FROM AUTHOR]

Copper‐based materials are efficient electrocatalysts for the conversion of CO2 to C2+ products, and most these materials are reconstructed in situ to regenerate active species. It is a challenge to precisely design precatalysts to obtain active sites for the CO2 reduction reaction (CO2RR). Herein, we develop a strategy based on local sulfur doping of a Cu‐based metal–organic framework precatalyst, in which the stable Cu−S motif is dispersed in the framework of HKUST‐1 (S‐HKUST‐1). The precatalyst exhibits a high ethylene selectivity in an H‐type cell with a maximum faradaic efficiency (FE) of 60.0 %, and delivers a current density of 400 mA cm−2 with an ethylene FE up to 57.2 % in a flow cell. Operando X‐ray absorption results demonstrate that Cuδ+ species stabilized by the Cu−S motif exist in S‐HKUST‐1 during CO2RR. Density functional theory calculations indicate the partially oxidized Cuδ+ at the Cu/CuxSy interface is favorable for coupling of the *CO intermediate due to the modest distance between coupling sites and optimized adsorption energy. [ABSTRACT FROM AUTHOR]

• In-situ nitrogen doping was achieved by one-step method, a series of Fe M (M = Pt, Pd, Ru, Rh) alloy electrocatalyst NPs with N-doped carbon coatings (Fe M @CN) was synthesized based on a noble metal doped Fe-MOF. • The optimal FePt@CN electrocatalyst demonstrates high electrocatalytic performance in an acidic electrolyte, with low overpotential, high mass activity, and excellent catalytic stability. • The optimal FeRu@CN electrocatalyst obtains an unexpectedly low overpotential of 18 mV in an alkaline electrolyte, which results in a current density of 10 mA cm−2 that is even better than a commercial Pt/C electrocatalyst with 20 wt% Pt loading. • The systematic study presented herein demonstrates that electrocatalysts suitable for different electrolytes can be found in the same alloy system, provides a universal and simple method for synthesizing transition and noble metal alloy electrocatalyst NPs that provides promising prospects for application in industrial electrolysis systems. The alloy catalyst formed by transition metal and a small amount of noble metal has become the most promising substitute for M-based (M = Pt, Pd, Ru, Rh) catalyst. However, due to the direct exposure of the metal core to the electrolyte, it is vulnerable to corrosion and oxidation, which in turn reduces the catalytic stability and is becoming a major obstacle to sustainable hydrogen production. The present work addresses this issue by developing a one-step immersion-adsorption-pyrolysis strategy for synthesizing FeM alloy nanoparticles with N-doped carbon coatings (FeM@CN) for use as electrocatalysts in the HER. The deliberately designed metal-organic framework material was used as the precursor of catalyst synthesis to achieve the carbon coatings and simultaneously the heteroatom in-situ doping for the alloy nanoparticles. The optimal FePt@CN demonstrates excellent catalytic stability and HER activity in an acidic electrolyte medium. The reactions obtain a small overpotential of 28 mV to achieve current densities of 10 mA cm−2, which are comparable to a high-performance commercial Pt/C electrocatalyst with a much higher Pt loading. The FeRu@CN also demonstrates an outstanding performance with an overpotential of only 18 mV to achieve a current density of 10 mA cm−2 in an alkaline medium. In-situ nitrogen doping was achieved by one-step method, a series of Fe M (M = Pt, Pd, Ru, Rh) alloy electrocatalyst NPs with N-doped carbon coatings (Fe M @CN) was synthesized based on a noble metal doped Fe metal organic framework. The systematic study presented herein demonstrates that electrocatalysts suitable for different electrolytes can be found in the same alloy system. [Display omitted] [ABSTRACT FROM AUTHOR]

The development of low-Pt catalysts is important for the large-scale application of Pt-based catalysts. Catalytic reactions mainly occur on the surface or interface of a material, and thus the surface properties of the catalyst will strongly affect their catalytic activity; this phenomenon has attracted widespread attention. Here, a series of Pt NPs with different chemical states and particle sizes were obtained by changing the light source wavelength, light time, and other conditions of light deposition synthesis. The Pt-TiO 2 catalyst has excellent potential in both photocatalytic hydrogen evolution (4.5 mmol·g−1·h−1) and electrocatalytic hydrogen evolution (26 mV@10 mA cm−2). We also found that the photocatalytic activity is more sensitive to the chemical state of Pt and that reducing the catalyst size can improve the electrocatalytic activity. This work not only provides a green and effective method to adjust the chemical state of precious metals on metal oxides but also helps to understand the impact of surface states on the catalytic process. A series of Pt NPs with different chemical states and sizes were embedded in TiO 2 (B) via a modified photochemical reduction method. The optimized Pt-TiO 2 (B) bifunctional catalyst exhibited excellent p-HER and e-HER catalytic activity. [Display omitted] • A series of Pt NPs with different chemical states and particle sizes were obtained by a photochemical strategy. • The optimized Pt-TiO 2 catalyst has excellent potential in both p-HER (4.5 mmol g−1 h−1) and e-HER (26 mV@10 mA cm−2). • The p-HER is more sensitive to the chemical state of Pt, and reducing the catalyst size improves the e-HER. • This work provides a new idea to promote catalytic activity by adjusting the catalyst's state and size. [ABSTRACT FROM AUTHOR]