Hydrogenation Activity Research Articles

A Cetylpyridinium Chloride Oral Rinse Reduces Salivary Viral Load in Randomized Controlled Trials.

Evaluating the antiviral potential of commercially available mouthrinses on SARS-CoV-2 holds potential for reducing transmission, particularly as novel variants emerge. Because SARS-CoV-2 is transmitted primarily through salivary and respiratory secretions and aerosols, strategies to reduce salivary viral burden in an antigen-agnostic manner are attractive for mitigating spread in dental, otolaryngology, and orofacial surgery clinics where patients may need to unmask. Patients (n = 128) with confirmed COVID-19-positive status within 10 days of symptom onset or positive test result were enrolled in a double-blind randomized controlled trial of Food and Drug Administration-approved mouthrinses containing active ingredients ethanol, hydrogen peroxide, povidone iodine, chlorhexidine gluconate, cetylpyridinium chloride (CPC), or saline. The CPC, ethanol, and sterile water rinses were followed in a second double-blind randomized controlled trial (n = 230). Participants provided a saliva sample before rinsing (baseline) and again at 30 and 60 min after rinse. Quantitative polymerase chain reaction was used to determine salivary SARS-CoV-2 viral load at all time points. An adjusted linear mixed-effect model was employed to compare viral load after rinsing relative to baseline. The rinse containing CPC significantly reduced salivary SARS-CoV-2 viral load 30 min postrinse relative to baseline (P = .015), whereas no other rinse significantly affected viral load at 30 min after rinsing. At 60 min postrinsing, no group had a significant reduction in SARS-CoV-2 copy number relative to baseline, indicating a rebound in salivary viral load over a 1-hour window. Participants indicated a fair to good rinsing experience with the CPC product and high willingness to use oral rinses before and during dental and medical health care visits. Our findings suggest that preprocedural oral rinsing could be implemented as a feasible, inexpensive approach to mitigate spread of SARS-CoV-2 and potentially other enveloped viruses for short periods, which is relevant to clinical procedures involving the nasal and oropharyngeal region. Rinsing with a cetylpyridinium chloride-containing mouthrinse can significantly reduce salivary SARS-CoV-2 viral load for up to 30 min; patients are willing to use mouthrinses in medical and dental settings to limit transmission risk in clinics.

Boosting C2+ Alcohols Selectivity and Activity in High-Current CO Electroreduction using Synergistic Cu/Zn Co-Catalysts.

The electrosynthesis of multi-carbon (C2+) alcohols, specifically ethanol and n-propanol through CO electroreduction (CORR) in H2O, presents a sustainable pathway for intermittent renewable energy storage and a low-carbon economy. However, achieving high selectivity for alcohol production at industrial current densities is kinetically hampered by side reactions such as ethylene generation and hydrogen evolution reaction, which result from competing adsorption of *CO and *H. In this study, we developed a Cu/Zn alloy catalyst to simultaneously enhance the activity and selectivity for alcohol production by increasing CO capture capacity and enriching active hydrogen on Cu sites. Our findings demonstrate that the Cu/5Zn alloy with a molar ratio of Cu to Zn of 95:5 exhibits a Faradaic efficiency of 50% for the selective electrosynthesis of C2+ alcohols during ampere-level CO electrolysis. Mechanistic investigations revealed that the Cu/Zn alloy promotes polarized Cu sites, enhancing CO adsorption while facilitating the spillover of hydrogen atoms from Zn to Cu sites, contributing to selective alcohol formation.

Boosting C2+ Alcohols Selectivity and Activity in High‐Current CO Electroreduction using Synergistic Cu/Zn Co‐Catalysts

The electrosynthesis of multi‐carbon (C2+) alcohols, specifically ethanol and n‐propanol through CO electroreduction (CORR) in H2O, presents a sustainable pathway for intermittent renewable energy storage and a low‐carbon economy. However, achieving high selectivity for alcohol production at industrial current densities is kinetically hampered by side reactions such as ethylene generation and hydrogen evolution reaction, which result from competing adsorption of *CO and *H. In this study, we developed a Cu/Zn alloy catalyst to simultaneously enhance the activity and selectivity for alcohol production by increasing CO capture capacity and enriching active hydrogen on Cu sites. Our findings demonstrate that the Cu/5Zn alloy with a molar ratio of Cu to Zn of 95:5 exhibits a Faradaic efficiency of 50% for the selective electrosynthesis of C2+ alcohols during ampere‐level CO electrolysis. Mechanistic investigations revealed that the Cu/Zn alloy promotes polarized Cu sites, enhancing CO adsorption while facilitating the spillover of hydrogen atoms from Zn to Cu sites, contributing to selective alcohol formation.

Synthesis of Bimetallic Pd/Pt Truncated Nanocubes and Their Catalytic Performance in Selective Hydrogenation of Acetophenone

A series of bimetallic Pd/Pt truncated nanocube catalysts with similar morphologies and particle sizes but different platinum contents were successfully synthesized using a colloidal method without using any capping agents. Their hydrogenation properties were systematically studied and compared with their monometallic Pd or Pt nanocrystal counterparts. The results of EDX-mapping and line scanning show that platinum was relatively uniformly distributed on the surface of the Pd/Pt bimetallic nanocrystals and was not selectively deposited at the corners of the nanocrystals. The results of the selective hydrogenation of acetophenone demonstrate that the hydrogenation rate and the carbonyl selectivity of bimetallic Pd/Pt truncated nanocube catalysts are generally much higher than those of their monometallic Pd or Pt nanocrystal counterparts. It was found that the electronic interaction between palladium and platinum in the bimetallic Pd/Pt truncated nanocube catalysts and the corresponding hydrogenation activity in the selective hydrogenation of acetophenone are closely related to the molar ratio between platinum and palladium and the thickness of the platinum layer in the bimetallic Pd/Pt truncated nanocube catalyst. With an increase in the Pt/Pd molar ratio in the bimetallic Pd/Pt truncated nanocube catalysts, the activity and carbonyl selectivity in the acetophenone hydrogenation reaction increase first, reach a maximum when the molar ratio of Pt/Pd is 0.02 and the theoretical thickness of Pt is 1.3 atomic layers, and then decrease with a further increase in the Pt/Pd ratio. The hydrogenation rate of acetophenone on the Pd/Pt0.02 catalyst reaches 1.07 × 103 mmol·h−1·gcat.−1, which is 79 and 75 times larger than that of the monometallic Pd and Pt nanocrystal catalysts, respectively. The maximum yield of the target product 1-phenylethanol on the Pd/Pt0.02 truncated nanocube catalyst reaches 97.2%, which is 6.6% and 16.7% higher than that of the monometallic Pd and Pt nanocrystal catalysts, respectively.

Highly Selective Hydrogenation of Nitriles to Primary Amines without an Additive Using Nanoscale Ni0-NiII/III-bTiO2 Heterojunctions.

Despite significant progress in the catalytic hydrogenation of nitriles, the persistent challenge of requiring additives to prevent condensation byproducts and achieve selectivity toward primary amines demands urgent attention. In this work, we present an integrated approach utilizing a ligand-bridged Ni-Ti bimetallic complex as a precursor to tune Ni0-NiO-NiO(OH) heterojunctions and phases of black titania (bTiO2) by controlling pyrolytic conditions. This tailored phase distribution and charge dynamics across heterojunctions create an effective balance of acidic and basic sites, enabling the direct hydrogenation of nitriles to primary amines without the need for additives. However, at elevated pyrolysis temperatures, this balanced composition begins to shift, with the loss of critical phases that alter the catalyst's structural and chemical properties. This shift reduces amphoteric behavior, resulting in decreased selectivity for primary amines and favoring the formation of condensation byproducts. The catalyst's structure, amphoteric nature, crystallinity, surface area, and active sites are comprehensively characterized using high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (PXRD), Fourier-transform infrared spectroscopy (FT-IR), temperature programmed desorption of ammonia (NH3-TPD), temperature programmed desorption of carbon dioxide (CO2-TPD), and CO2 adsorption techniques. The magnetically retrievable catalyst exhibited excellent functional group tolerance, high selectivity, multiple reusability, broad substrate scope, and high activity for nitrile hydrogenation to primary amines, with the potential for advanced catalytic hydrogenation of other functional groups.

Enhanced resistance to poisoning of Pd in alkynes semi‐hydrogenation by metal–ligand electronic interactions

AbstractGiven that the retention of nitrogen readily renders active site poisoning, designing versatile catalysts characterized by notable selectivity and even resistance to poisoning for alkyne semi‐hydrogenation under nitrogen‐containing conditions is considerably challenging. In this article, oxanilide‐decorated Pd/C (Pd/C‐oxa) catalyst is facilely synthesized by leveraging impregnation‐coordination, which exhibit remarkable performance in the semi‐hydrogenation of nitrogen‐containing alkynes, with ultrahigh turnover frequency (TOF) of 15,831 h−1 and selectivity of 97.2%. Strikingly, it still sustains TOF of 12,137 h−1 in a sulfur‐containing system, demonstrating distinguished tolerance to sulfur. Comprehensive studies corroborate that oxanilide tunes the electron density of Pd by constructing metal–ligand electronic interactions, facilitating hydrogen activation. Simultaneously, the reaction microenvironment is optimized, which effectively promotes the desorption of nitrogen‐containing olefins and attenuates the aggregation of nitrogen on the Pd surface. This strategy is universal and holds promising industrial applications, making it appropriate for use in commercial Pd/C catalysts as well.

Regulating Interfacial Hydrogen‐Bonding Networks by Implanting Cu Sites with Perfluorooctane to Accelerate CO2 Electroreduction to Ethanol

Efficient CO2 electroreduction (CO2RR) to ethanol holds promise to generate value‐added chemicals and harness renewable energy simultaneously. Yet, it remains an ongoing challenge due to the competition with thermodynamically more preferred ethylene production. Herein, we presented a CO2 reduction predilection switch from ethylene to ethanol (ethanol‐to‐ethylene ratio of ~5.4) by inherently implanting Cu sites with perfluorooctane to create interfacial non‐covalent interactions. The 1.83%F‐Cu2O organic‐inorganic hybrids (OIHs) exhibited an extraordinary ethanol faradaic efficiency (FEethanol) of ∼55.2%, with an impressive ethanol partial current density of 166 mA cm‐2 and excellent robustness over 60 hours of continuous operation. This exceptional performance ranks our 1.83%F‐Cu2O OIHs among the best‐performing ethanol‐oriented CO2RR electrocatalysts. Our findings identified that C8F18 could strengthen the interfacial hydrogen bonding connectivity, which consequently promotes the generation of active hydrogen species and preferentially favors the hydrogenation of *CHCOH to *CHCHOH, thus switching the reaction from ethylene‐preferred to ethanol‐oriented. The presented investigations highlight opportunities for using noncovalent interactions to tune the selectivity of CO2 electroreduction to ethanol, bringing it closer to practical implementation requirements.

Surface Structure Dependent Activation of Hydrogen over Metal Oxides during Syngas Conversion.

Despite the extensive studies on the adsorption and activation of hydrogen over metal oxides, it remains a challenge to investigate the structure-dependent activation of hydrogen and its selectivity mechanism in hydrogenation reactions. Herein we take spinel and solid solution MnGaOx with a similar bulk chemical composition and study the hydrogen activation mechanism and reactivity in syngas conversion. The results show that MnGaOx-Solid Solution (MnGaOx-SS) is a typical Mn-doped hexagonal close-packed (HCP) Ga2O3 with a Ga-rich surface. Upon exposure to hydrogen, Ga-H and O-H species are simultaneously generated. Ga-H species are highly active but unselective in CO activation, forming CHxO, and ethylene hydrogenation, forming ethane. In contrast, MnGaOx-Spinel is a face-centered-cubic (FCC) spinel phase featuring a Mn-rich surface, thus effectively suppressing the formation of Ga-H species. Interestingly, only part of the O-H species are active for CO activation while the O-H species are inert for olefin hydrogenation over MnGaOx-Spinel. Therefore, MnGaOx-Spinel exhibits a higher activity and higher light-olefin selectivity than MnGaOx-SS in combination with SAPO-18 during syngas conversion. These fundamental understandings are essential to guide the design and further optimization of metal oxide catalysts for selectivity control in hydrogenations.

Regulating Interfacial Hydrogen-Bonding Networks by Implanting Cu Sites with Perfluorooctane to Accelerate CO2 Electroreduction to Ethanol.

Efficient CO2 electroreduction (CO2RR) to ethanol holds promise to generate value-added chemicals and harness renewable energy simultaneously. Yet, it remains an ongoing challenge due to the competition with thermodynamically more preferred ethylene production. Herein, we presented a CO2 reduction predilection switch from ethylene to ethanol (ethanol-to-ethylene ratio of ~5.4) by inherently implanting Cu sites with perfluorooctane to create interfacial non-covalent interactions. The 1.83%F-Cu2O organic-inorganic hybrids (OIHs) exhibited an extraordinary ethanol faradaic efficiency (FEethanol) of ∼55.2%, with an impressive ethanol partial current density of 166 mA cm-2 and excellent robustness over 60 hours of continuous operation. This exceptional performance ranks our 1.83%F-Cu2O OIHs among the best-performing ethanol-oriented CO2RR electrocatalysts. Our findings identified that C8F18 could strengthen the interfacial hydrogen bonding connectivity, which consequently promotes the generation of active hydrogen species and preferentially favors the hydrogenation of *CHCOH to *CHCHOH, thus switching the reaction from ethylene-preferred to ethanol-oriented. The presented investigations highlight opportunities for using noncovalent interactions to tune the selectivity of CO2 electroreduction to ethanol, bringing it closer to practical implementation requirements.

Direct synthesis of liquid hydrocarbons from CO2 and H2 over bifunctional ZnCrOx-НZSM-5 combined and composite catalysts in a single reactor

A one-stage synthesis of gasoline fraction from CO2 and H2 was carried out on Zn-Cr–oxide-zeolite combined and composite catalysts. It was found that after oxidative and reduction treatment the catalysts contain ZnO and ZnCr2O4 phases. The one-step coprecipitation of zinc and chromium salts in the presence of zeolite allows obtaining an active bifunctional composite catalyst, each particle of which contains Zn-Cr oxide and zeolite components. A synergistic catalysis due to a closer distance of metal and acid sites increased the efficiency of such a catalyst in CO2 hydrogenation. It was found that the optimal temperature of oxidative activation of the composite catalyst is 400 ° C. With an increase in the temperature of oxidative treatment of the composite catalyst from 400 to 500°C, part of the zinc leaves the structure of the non-stoichiometric spinel and leads to a decrease in the basicity of the catalyst, which is responsible for the activation of CO2 on surface oxygen vacancies. Agglomerated ZnO particles blocked the pores and reduced their volume, as well as the specific surface of the catalyst. At the same time, the total acidity of the catalyst decreased. ZnO-species, which have hydrogenating activity, under the reaction conditions removed alkenes from the reaction cycle and thereby reduced the C5+–selectivity of the composite catalyst. Among the studied catalysts, the ZnCrOx-НZSM-5/Al2O3(400) composite catalyst in the tail-gas recirculation mode at 380°C and 10 MPa demonstrated high CO2 conversion of 25% and high selectivity for C5+–HCs of 53 wt% with a high content of isoalkanes 71 wt% for 60 hours. The methane content in the tail-gas did not exceed 3 vol%. The results obtained will be used to develop approaches to creating effective catalysts for the one-stage CO2 hydrogenation into valuable petrochemical products.

Enhanced conversion of rosin to polymerized rosin with reusable Brønsted acid deep eutectic solvent

With the depletion of non-renewable resources and the increasingly serious environmental problems, the production of high value-added polymer materials using renewable resources as raw materials had aroused great interest. Deep eutectic solvent (DES)-[ChCl][TfOH]2 (prepared by choline chloride (ChCl) and trifluoromethanesulfonic acid (TfOH)), with suitable acid strength (H0=0.98) and active hydrogen, had been successfully used for enhanced conversion of rosin to polymerized rosin efficiently, under the conditions of rosin =15 g, mDES: mrosin=30 %, T=110℃ and t=9 h, polymerized rosin with high softening point (150.40℃) and low acid value (124.21 mg KOH/g) could be produced efficiently. [ChCl][TfOH]2 required no special treatment then could be reused for 5 times without significant loss of catalytic performance, on this basis, the green synthesis technology of polymerized rosin under DES system was given, not only promoted the further application of polymerized rosin, but also realized the high value-added utilization of renewable resource rosin. In addition, the formation mechanism of DES was systematically explained through DFT calculation, the reaction mechanism of rosin polymerization over [ChCl][TfOH]2 was explored, which could provide theoretical basis for further research.

Synergistic regulation of dual thresholds: Hydroxyl occupancy and carbon species in the targeted catalytic hydrocracking of lignite

The preparation of carbon-based catalyst supports from low-grade lignite, followed by its self-catalytic hydrocracking to produce lignite-derived aromatic compounds, is crucial for achieving efficient lignite utilization and expanding aromatic compound sources. During lignite catalytic hydrocracking, the uncontrolled diffusive migration of active hydrogen (H*) and insufficient protection of aromatic rings reduce the yield of aromatic compounds. Using Heishan lignite as the raw material, we employed a relay process of thermal-induced self-assembly and oxidation-mediated carbon distortion for fabricating the Co3O4/AC&GC-S-600 composite material, which features an optimal hydroxyl occupancy ratio and a balanced combination of amorphous carbon/graphite carbon (AC/GC) types. The optimal hydroxyl occupancy threshold balances Co3O4 dispersion and hydrophilicity, facilitating the efficient formation and directional migration of H* through synergistic interaction between Co3O4 and H2O. The adequate threshold of AC/GC ratio regulates substrate adsorption, activation, and inhibition of aromatic hydrogenation, enhancing selective C–O bridge bond cleavage and preserving the unsaturation of aromatic rings. The synergistic regulation of dual thresholds promotes the rapid formation and the directional migration of H*, enabling efficient conversion of Heishan lignite to aromatic compounds (45.8% conversion, 80.8% selectivity) under mild conditions. Characterization techniques, experimental analyses, kinetic studies, and density functional theory calculations confirm that thermally induced self-assembly and oxidation-mediated carbon distortion are crucial for redistributing the carbon framework of the Heishan lignite matrix and regulating the optimal dual thresholds of hydroxyl occupancy and AC/GC types, which are essential for the catalytic hydrocracking of Heishan lignite to aromatic compounds. This strategy provides a scientific basis for selective catalytic production of lignite-based aromatic compounds, thereby supporting its clean and efficient utilization.

Mechanical activation assisted synthesis of atomically dispersed cobalt catalysts supported on N, P co-doped cellulose-derived carbon for nitrobenzene hydrogenation

Modulating the coordination structure of active center atoms of atomically dispersed metal catalysts has emerged as a critical strategy to further enhance the catalytic performance for selective hydrogenation. Herein, we report the successful synthesis of atomically dispersed cobalt catalysts supported on N, P co-doped cellulose-derived carbon (Co1/NPC) via a mechanical activation assisted synthesis method. The introduction of P and N atoms modifies the electronic structure of Co atoms by forming Co–Nx and Co–Px structures, enhancing their ability to dissociate H2 and adsorb nitroarenes, thereby significantly boosting the hydrogenation activity. Consequently, the Co1/NPC catalyst demonstrates outstanding catalytic activity for the selective hydrogenation of nitrobenzene, achieving 99 % conversion and selectivity with a high TOF of 507 h−1, far outperforming the benchmark Co1/NC (TOF of 4 h−1) and CoNPs/NPC catalysts (TOF of 10 h−1). Moreover, Co1/NPC catalysts possess exceptional stability and satisfactory universality. This study provides an efficient and practical catalyst for the production of nitroanilines via the selective hydrogenation of nitroarenes.

Crystal facet engineering of Pd/TiO2 to boost the activity and selectivity for nitroarenes hydrogenation

Crystal facet engineering of Pd/TiO2 to boost the activity and selectivity for nitroarenes hydrogenation

Advancing equitable value chains for the global hydrogen economy

Hydrogen is a rapidly growing focus for countries seeking to develop green industries, but there are many questions about how the nascent global hydrogen economy will develop, and what this implies for equitable sharing of benefits and burdens between nations. In this perspective we summarize emerging trends in national hydrogen strategies and develop recommendations for researchers and policymakers to center equity in hydrogen development. This will require integrating innovation and development perspectives on international technology transfer, developing more detailed representation of hydrogen trade in systems models, building equity considerations into national and international planning processes, and establishing robust technology transfer efforts. Policymakers will also need to grapple with the difficulties of verifying life cycle emissions of hydrogen if hydrogen trade emerges as a significant trend, potentially requiring new methods of emissions accounting and trade reforms that prioritize international equity.

Enhanced photocatalytic hydrogen and oxygen evolution activity by two-dimensional van der Waals AlSb/ZnO heterostructure: A first-principles study

Photocatalytic water splitting facilitates the generation of green hydrogen energy by transforming renewable solar energy into chemical energy. This paper investigated the electronic, optical, and photocatalytic properties of AlSb/ZnO van der Waals (vDW) heterostructure using density functional theory. AlSb/ZnO, a semiconductor heterostructure with an indirect bandgap, was energetically stable with a formation energy of −0.4 eV as well as dynamically and thermally stable. The band edges of the 2D heterostructure maintained the essential redox energy levels for complete water splitting, allowing hydrogen and oxygen generation. Moreover, the heterostructure exhibited a high absorption coefficient in the visible region of the solar spectrum compared to the individual AlSb and ZnO monolayers. We revealed low barrier potential at neutral pH conditions for oxygen and hydrogen evolution reactions from the Gibbs free energy calculation without any external potential. Our study additionally showed the solar-to-hydrogen efficiency of 27.93% and a carrier utilization efficiency of 42.83%, indicating the AlSb/ZnO heterostructure as an excellent water splitting photocatalyst with remarkable potential for fuel cells and energy storage applications.

Selective CO2 hydrogenation to methanol over a novel ternary In-Co-Zr catalyst

To address the challenges of global warming and energy shortages, the technology to convert CO2 into methanol is of great significance Indium-cobalt catalysts have attracted widespread attention due to their significant activity and excellent stability. Herein, In-Co and In-Co-Zr catalyst rich in In2O3 were prepared through a citric acid-assisted co-precipitation method. The results show that the In-Co-Zr catalyst can significantly enhance the activity for hydrogenating CO2 to methanol, achieving a CO2 conversion rate of 17.4 % and a methanol selectivity of 77.7 % under the conditions (5.0 MPa, 310 °C, GHSV = 10.28 l·gcat-1·h-1, H2/CO2 ratio of 4). At a GHSV of 48 l·gcat-1·h-1, the space–time yield of methanol was 0.79 gMeOH·gcat-1·h-1, and the catalyst exhibited stable catalytic activity over a continuous reaction period of 120 h. It was revealed that the incorporation of ZrO2 could significantly improve methanol selectivity of In-Co catalyst. Moreover, an increased oxygen vacancy and strong interaction of the In-Co-Zr catalysts are conducive to improving the CO2 adsorption strength and capacity. It is expected that this novel ternary In-Co-Zr catalyst could inspire new opportunities for designing and developing multi-component hybrid catalysts for highly active, stable and selective CO2 hydrogenation to methanol

High-homogeneous recyclable self-cured epoxy resins based on imine

The production of high-performance epoxy resins currently depends on combining rigid epoxy oligomers and non-flexible hardeners. However, the high melting points and incompatibilities of raw materials, along with the inhomogeneous crosslinked networks of thermoset resins, challenge the development of high-performance epoxy resins simultaneously enhancing strength and toughness with excellent processing properties. To address this issue, we propose a self-curing strategy to obtain a novel thermosetting epoxy resin by simply melting the epoxy oligomers containing the Schiff base structure. The mechanism of self-cured was also revealed by density functional theory. Remarkably, this method eliminates the need for curing agents, catalysts, or active hydrogen structures. The resulting self-cured epoxy resin (VEP-SC) simplifies processing steps. In particular, VEP-SC forms a more homogeneous cross-linked network and exhibits superior mechanical properties due to the unique preparation method. Compared to traditional thermosetting epoxy cured with a curing agent, the tensile strength, elongation at break, and flexural strength of VEP-SC were 133.4 %, 168.4 %, and 276.2 % higher than those of VEP-MeHHPA, respectively. Furthermore, the Schiff base structure imparts the vitrimeric behavior of self-cured epoxy resin, achieving recyclability. This approach provides innovative solutions for developing versatile and high-performance epoxy resins.

Reusable metal-free mesoporous carbon-catalyzed reductive N-formylation of nitroarenes and quinolines

The high-value transformation of nitrogen-containing compounds through a facile, cost-effective, and eco-friendly one-pot strategy holds significant importance. However, this process typically involves the use of metal catalysts and is limited by low activity as well as the requirement of high temperature and pressure. Herein, we describe a general and efficient metal-free N-doped mesoporous carbon material using well-defined ligand 1,10-phenanthroline as the precursor and silica colloid as the hard template. Formic acid is both a reducing agent and a formylation reagent, and structurally distinct mono- or multi-substituted nitroarenes and quinolines can be selectively N-formylation in a one-pot method. The catalyst can be easily recovered without observable loss of efficiency for ten consecutive uses. The control experiments and density functional theory (DFT) calculations indicate that formic acid mainly obtains active hydrogen in the form of O–H bond cleavage, which benefits from the strong adsorption and enhanced activity generated by the interaction between graphitic nitrogen species in the catalyst and formic acid. The excellent catalytic performance of the meso-phen-X catalyst is attributed to the synergistic effect of graphitic N and large specific surface area, providing a promising method for the development of non-metallic catalyst-modified carbon materials.

Bucket effect of Cobalt Nanoparticles and Single Atoms in Nitroarenes Transfer Hydrogenation

Synergetic metal nanoparticles (NPs) and single atoms hold significant potential in reactions that require activating multiple substrate molecules. However, due to the differences in adsorption, activation and kinetics among distinct substrates during the multistep reaction process, the synergy and matching relationship between metal NPs and single atoms remain unclear. In this work, we synthesized a series of Co1-NP/CNT@CN-X dual-site catalysts with tunable molar ratios (X%) of Co single atoms to total Co species through a coordination site regulation (CSR) strategy and investigated the bucket effect of the dual active sites in the transfer hydrogenation of nitro compounds. Density functional theory calculations reveal that active hydrogen generation from ammonia borane hydrolysis primarily occurs at the surface of Co NPs, while nitroarenes hydrogenation predominantly takes place at Co single atoms, which is consistent with experimental findings. The optimized Co1-NP/CNT@CN-7.6 maintains high selectivity for nitro hydrogenation (> 99.9%) and exhibits conversion (99.9%) nearly 3.7 times that of the original Co1-NP/CNT@CN-1.6 catalyst (27%), achieved by overcoming the bucket effect between Co NPs and single atoms. This work not only elucidates the synergistic mechanisms of dual sites in transfer hydrogenation, but also establishes that optimizing matching effect is an effective approach to significantly enhance their catalytic performance.