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1.
Nat Commun ; 15(1): 6174, 2024 Jul 22.
Article in English | MEDLINE | ID: mdl-39039047

ABSTRACT

The inactivation of natural enzymes by radiation poses a great challenge to their applications for radiotherapy. Single-atom nanozymes (SAzymes) with high structural stability under such extreme conditions become a promising candidate for replacing natural enzymes to shrink tumors. Here, we report a CuN3-centered SAzyme (CuN3-SAzyme) that exhibits higher peroxidase-like catalytic activity than a CuN4-centered counterpart, by locally regulating the coordination environment of single copper sites. Density functional theory calculations reveal that the CuN3 active moiety confers optimal H2O2 adsorption and dissociation properties, thus contributing to high enzymatic activity of CuN3-SAzyme. The introduction of X-ray can improve the kinetics of the decomposition of H2O2 by CuN3-SAzyme. Moreover, CuN3-SAzyme is very stable after a total radiation dose of 500 Gy, without significant changes in its geometrical structure or coordination environment, and simultaneously still retains comparable peroxidase-like activity relative to natural enzymes. Finally, this developed CuN3-SAzyme with remarkable radioresistance can be used as an external field-improved therapeutics for enhancing radio-enzymatic therapy in vitro and in vivo. Overall, this study provides a paradigm for developing SAzymes with improved enzymatic activity through local coordination manipulation and high radioresistance over natural enzymes, for example, as sensitizers for cancer therapy.


Subject(s)
Copper , Hydrogen Peroxide , Peroxidase , Radiation Tolerance , Copper/chemistry , Animals , Humans , Hydrogen Peroxide/chemistry , Hydrogen Peroxide/metabolism , Peroxidase/metabolism , Peroxidase/chemistry , Mice , Cell Line, Tumor , Catalysis/radiation effects , Kinetics
2.
J Am Chem Soc ; 2024 Jul 25.
Article in English | MEDLINE | ID: mdl-39052434

ABSTRACT

As the most promising hydrogen evolution reaction (HER) electrocatalysts, platinum (Pt)-based catalysts still struggle with sluggish kinetics and expensive costs in alkaline media. Herein, we accelerate the alkaline hydrogen evolution kinetics by optimizing the local environment of Pt species and metal oxide heterointerfaces. The well-dispersed PtRu bimetallic clusters with adjacent MO2-x (M = Sn and Ce) on carbon nanotubes (PtRu/CNT@MO2-x) are demonstrated to be a potential electrocatalyst for alkaline HER, exhibiting an overpotential of only 75 mV at 100 mA cm-2 in 1 M KOH. The excellent mass activity of 12.3 mA µg-1Pt+Ru and specific activity of 32.0 mA cm-2ECSA at an overpotential of 70 mV are 56 and 64 times higher than those of commercial Pt/C. Experimental and theoretical investigations reveal that the heterointerfaces between Pt clusters and MO2-x can simultaneously promote H2O adsorption and activation, while the modification with Ru further optimizes H adsorption and H2O dissociation energy barriers. Then, the matching kinetics between the accelerated elementary steps achieved superb hydrogen generation in alkaline media. This work provides new insight into catalytic local environment design to simultaneously optimize the elementary steps for obtaining ideal alkaline HER performance.

3.
J Am Chem Soc ; 2024 Jul 20.
Article in English | MEDLINE | ID: mdl-39031766

ABSTRACT

Lower olefins are widely used in the chemical industry as basic carbon-based feedstocks. Here, we report the catalytic system featuring isolated single-atom sites of iridium (Ir1) that can function within the entire temperature range of 300-600 °C and transform alkanes with conversions close to thermodynamics-dictated levels. The high turnover frequency values of the Ir1 system are comparable to those of homogeneous catalytic reactions. Experimental data and theoretical calculations both indicate that Ir1 is the primary catalytic site, while the coordinating C and N atoms help to enhance the activity and stability, respectively; all three kinds of elements cooperatively contribute to the high performance of this novel active site. We have further immobilized this catalyst on particulate Al2O3, and we found that the resulting composite system under mimicked industrial conditions could still give high catalytic performances; in addition, we have also developed and established a new scheme of periodical in situ regeneration specifically for this composite particulate catalyst.

4.
Nat Commun ; 15(1): 5630, 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38965207

ABSTRACT

The chemical recycling of polyester wastes is of great significance for sustainable development, which also provides an opportunity to access various oxygen-containing chemicals, but generally suffers from low efficiency or separation difficulty. Herein, we report anatase TiO2 supported Ru and Mo dual-atom catalysts, which achieve transformation of various polyesters into corresponding diols in 100% selectivity via hydrolysis and subsequent hydrogenation in water under mild conditions (e.g., 160 °C, 4 MPa). Compelling evidence is provided for the coexistence of Ru single-atom and O-bridged Ru and Mo dual-atom sites within this kind of catalysts. It is verified that the Ru single-atom sites activate H2 for hydrogenation of carboxylic acid derived from polyester hydrolysis, and the O-bridged Ru and Mo dual-atom sites suppress hydrodeoxygenation of the resultant alcohols due to a high reaction energy barrier. Notably, this kind of dual-atom catalysts can be regenerated with high activity and stability. This work presents an effective way to reconstruct polyester wastes into valuable diols, which may have promising application potential.

5.
J Am Chem Soc ; 146(29): 20518-20529, 2024 Jul 24.
Article in English | MEDLINE | ID: mdl-38995120

ABSTRACT

Despite the extensive development of non-noble metals for the N-alkylation of amines with alcohols, the exploitation of catalysts with high selectivity, activity, and stability still faces challenges. The controllable modification of single-atom sites through asymmetric coordination with a second heteroatom offers new opportunities for enhancing the intrinsic activity of transition metal single-atom catalysts. Here, we prepared the asymmetric N/P hybrid coordination of single-atom Co1-N3P1 by absorbing the Co-P complex on ZIF-8 using a concise impregnation-pyrolysis process. The catalyst exhibits ultrahigh activity and selectivity in the N-alkylation of aniline and benzyl alcohol, achieving a turnover number (TON) value of 3480 and a turnover frequency (TOF) value of 174-h. The TON value is 1 order of magnitude higher than the reported catalysts and even 37-fold higher than that of the homogeneous catalyst CoCl2(PPh3)2. Furthermore, the catalyst maintains its high activity and selectivity even after 6 cycles of usage. Controlling experiments and isotope labeling experiments confirm that in the asymmetric Co1-N3P1 system, the N-alkylation of aniline with benzyl alcohol proceeds via a transfer hydrogenation mechanism involving the monohydride route. Theoretical calculations prove that the superior activity of asymmetric Co1-N3P1 is attributed to the higher d-band energy level of Co sites, which leads to a more stable four-membered ring transition state and a lower reaction energy barrier compared to symmetrical Co1-N4.

6.
Angew Chem Int Ed Engl ; : e202411396, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-39010646

ABSTRACT

Electrochemical nitrate reduction method (NitRR) is a low-carbon, environmentally friendly, and efficient method for synthesizing ammonia, which has received widespread attention in recent years. Copper-based catalysts have a leading edge in nitrate reduction due to their good adsorption of *NO3. However, the formation of active hydrogen (*H) on Cu surfaces is difficult and insufficient, resulting in a large amount of the by-product NO2-. In this work, Pd single atoms suspended on the interlayer unsaturated bonds of CuO atoms formed due to dislocations (Pd-CuO) were prepared by low temperature treatment, and the Pd single atoms located on the dislocations were subjected to shear stress and the dynamic effect of support formation to promote the conversion of nitrate into ammonia. The catalysis had an ammonia yield of 4.2 mol.gcat-1. h-1, and a Faraday efficiency of 90% for ammonia production at -0.5 V vs. RHE. Electrochemical in-situ characterization and theoretical calculations indicate that the dynamic effects of Pd single atoms and carriers under shear stress obviously promote the production of active hydrogen, reduce the reaction energy barrier of the decision-making step for nitrate conversion to ammonia, further promote ammonia generation.

7.
Angew Chem Int Ed Engl ; : e202405637, 2024 Jun 02.
Article in English | MEDLINE | ID: mdl-38825570

ABSTRACT

Directly coupling N2 and CO2 to synthesize urea by photocatalysis paves a sustainable route for urea synthesis, but its performance is limited by the competition of photogenerated electrons between N2 and CO2, as well as the underutilized photogenerated holes. Herein, we report an efficient urea synthesis process involving photogenerated electrons and holes in respectively converting CO2 and N2 over a redox heterojunction consisting of WO3 and Ni single-atom-decorated CdS (Ni1-CdS/WO3). For the photocatalytic urea synthesis from N2 and CO2 in pure water, Ni1-CdS/WO3 attained a urea yield rate of 78 µM h-1 and an apparent quantum yield of 0.15 % at 385 nm, which ranked among the best photocatalytic urea synthesis performance reported. Mechanistic studies reveal that the N2 was converted into NO species by ⋅OH radicals generated from photogenerated holes over the WO3 component, meanwhile, the CO2 was transformed into *CO species over the Ni site by photogenerated electrons. The generated NO and *CO species were further coupled to form *OCNO intermediate, then gradually transformed into urea. This work emphasizes the importance of reasonably utilizing photogenerated holes in photocatalytic reduction reactions.

8.
Angew Chem Int Ed Engl ; : e202404968, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38830833

ABSTRACT

The heteroatom substitution is considered as a promising strategy for boosting the redox kinetics of transition metal compounds in hybrid supercapacitors (HSCs) although the dissimilar metal identification and essential mechanism that dominate the kinetics remain unclear. It is presented that d-p orbital hybridization between the metal and electrolyte ions can be utilized as a descriptor for understanding the redox kinetics. Herein, a series of Co, Fe and Cu heteroatoms are respectively introduced into Ni3Se4 cathodes, among them, only the moderate Co-substituted Ni3Se4 can hold the optimal d-p orbital hybridization resulted from the formed more unoccupied antibonding states π*. It inevitably enhances the interfacial charge transfer and ensures the balanced OH- adsorption-desorption to accelerate the redox kinetics validated by the lowest reaction barrier (0.59 eV, matching well with the theoretical calculations). Coupling with the lower OH- diffusion energy barrier, the prepared cathode delivers ultrahigh rate capability (~68.7 % capacity retention even the current density increases by 200 times), and an assembled HSC also presents high energy/power density. This work establishes the principles for determining heteroatoms and deciphers the underlying effects of the heteroatom substitution on improving redox kinetics and the rate performance of battery-type electrodes from a novel perspective of orbital-scale manipulation.

9.
Angew Chem Int Ed Engl ; : e202408193, 2024 May 27.
Article in English | MEDLINE | ID: mdl-38802317

ABSTRACT

Hydrolysis of ammonia borane (NH3BH3, AB) involves multiple undefined steps and complex adsorption and activation, so single or dual sites are not enough to rapidly achieve the multi-step catalytic processes. Designing multi-site catalysts is necessary to enhance the catalytic performance of AB hydrolysis reactions but revealing the matching reaction mechanisms of AB hydrolysis is a great challenge. In this work, we propose to construct RuPt-Ti multi-site catalysts to clarify the multi-site tandem activation mechanism of AB hydrolysis. Experimental and theoretical studies reveal that the multi-site tandem mode can respectively promote the activation of NH3BH3 and H2O molecules on the Ru and Pt sites as well as facilitate the fast transfer of *H and the desorption of H2 on Ti sites at the same time. RuPt-Ti multi-site catalysts exhibit the highest turnover frequency (TOF) of 1293 min-1 for AB hydrolysis reaction, outperforming the single-site Ru, dual-site RuPt and Ru-Ti catalysts. This study proposes a multi-site tandem concept for accelerating the dehydrogenation of hydrogen storage material, aiming to contribute to the development of cleaner, low-carbon, and high-performance hydrogen production systems.

10.
Angew Chem Int Ed Engl ; 63(30): e202316755, 2024 Jul 22.
Article in English | MEDLINE | ID: mdl-38739420

ABSTRACT

The hydrazine oxidation-assisted H2 evolution method promises low-input and input-free hydrogen production. However, developing high-performance catalysts for hydrazine oxidation (HzOR) and hydrogen evolution (HER) is challenging. Here, we introduce a bifunctional electrocatalyst α-MoC/N-C/RuNSA, merging ruthenium (Ru) nanoclusters (NCs) and single atoms (SA) into cubic α-MoC nanoparticles-decorated N-doped carbon (α-MoC/N-C) nanowires, through electrodeposition. The composite showcases exceptional activity for both HzOR and HER, requiring -80 mV and -9 mV respectively to reach 10 mA cm-2. Theoretical and experimental insights confirm the importance of two Ru species for bifunctionality: NCs enhance the conductivity, and its coexistence with SA balances the H ad/desorption for HER and facilitates the initial dehydrogenation during the HzOR. In the overall hydrazine splitting (OHzS) system, α-MoC/N-C/RuNSA excels as both anode and cathode materials, achieving 10 mA cm-2 at just 64 mV. The zinc hydrazine (Zn-Hz) battery assembled with α-MoC/N-C/RuNSA cathode and Zn foil anode can exhibit 97.3 % energy efficiency, as well as temporary separation of hydrogen gas during the discharge process. Therefore, integrating Zn-Hz with OHzS system enables self-powered H2 evolution, even in hydrazine sewage. Overall, the amalgamation of NCs with SA achieves diverse catalytic activities for yielding multifold hydrogen gas through advanced cell-integrated-electrolyzer system.

11.
Angew Chem Int Ed Engl ; : e202406883, 2024 May 24.
Article in English | MEDLINE | ID: mdl-38783773

ABSTRACT

Consuming a substantial quantum of energy (~165 TW h), the chlor-alkali industry garners considerable scholarly and industrial interest, with the anode reaction involving the oxidation of chloride ions being a paramount determinant of reaction rates. While the dimensionally stable anode (DSA) displays commendable catalytic activity and longevity, they rely on precious metals and exhibit a non-negligible side reaction in sodium hypochlorite (NaClO) production, underscoring the appeal of metal-free alternatives. However, the molecules and systems currently available are characterized by intricate complexity and are not amenable to large-scale production. Herein, we have successfully developed an economical and highly efficient molecular catalyst, demonstrating superior performance compared with the former organic molecules in the chloride ion oxidation process (COP) for the production of both chlorine gas (Cl2) and NaClO. The molecule of 2N only needs 92 mV to reach a current density of 1000 mA cm-2, with a small cost of only 0.002 $ g-1. Furthermore, we propose a novel mechanism underpinned by non-covalent interactions, serving as the foundation for an innovative approach to the design of efficient anodes for the COP.

12.
Small ; : e2402050, 2024 May 27.
Article in English | MEDLINE | ID: mdl-38801298

ABSTRACT

Electrocatalysis is a very attractive way to achieve a sustainable carbon cycle by converting CO2 into organic fuels and feedstocks. Therefore, it is crucial to design advanced electrocatalysts by understanding the reaction mechanism of electrochemical CO2 reduction reaction (eCO2RR) with multiple electron transfers. Among electrocatalysts, dual-atom catalysts (DACs) are promising candidates due to their distinct electronic structures and extremely high atomic utilization efficiency. Herein, the eCO2RR mechanism and the identification of intermediates using advanced characterization techniques, with a particular focus on regulating the critical intermediates are systematically summarized. Further, the insightful understanding of the functionality of DACs originates from the variable metrics of electronic structures including orbital structure, charge distribution, and electron spin state, which influences the active sites and critical intermediates in eCO2RR processes. Based on the intrinsic relationship between variable metrics and critical intermediates, the optimized strategies of DACs are summarized containing the participation of synergistic atoms, engineering of the atomic coordination environment, regulation of the diversity of central metal atoms, and modulation of metal-support interaction. Finally, the challenges and future opportunities of atomically dispersed catalysts for eCO2RR processes are discussed.

13.
ACS Nano ; 18(20): 13286-13297, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38728215

ABSTRACT

The ideal interface design between the metal and substrate is crucial in determining the overall performance of the alkyne semihydrogenation reaction. Single-atom alloys (SAAs) with isolated dispersed active centers are ideal media for the study of reaction effects. Herein, a charge-asymmetry "armor" SAA (named Pd1Fe SAA@PC), which consists of a Pd1Fe alloy core and a semiconducting P-doped C (PC) shell, is rationally designed as an ideal catalyst for the selective hydrogenation of alkynes with high efficiency. Multiple spectroscopic analyses and density functional theory calculations have demonstrated that Pd1Fe SAA@PC is dual-regulated by lattice tensile and Schottky effects, which govern the selectivity and activity of hydrogenation, respectively. (1) The PC shell layer applied an external traction force causing a 1.2% tensile strain inside the Pd1Fe alloy to increase the reaction selectivity. (2) P doping into the C-shell layer realized a transition from a p-type semiconductor to an n-type semiconductor, thereby forming a unique Schottky junction for advancing alkyne semihydrogenation activity. The dual regulation of lattice strain and the Schottky effect ensures the excellent performance of Pd1Fe SAA@PC in the semihydrogenation reaction of phenylethylene, achieving a conversion rate of 99.9% and a selectivity of 98.9% at 4 min. These well-defined interface modulation strategies offer a practical approach for the rational design and performance optimization of semihydrogenation catalysts.

14.
Angew Chem Int Ed Engl ; 63(21): e202400625, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38556897

ABSTRACT

Single-metal atomic sites and vacancies can accelerate the transfer of photogenerated electrons and enhance photocatalytic performance in photocatalysis. In this study, a series of nickel hydroxide nanoboards (Ni(OH)x NBs) with different loadings of single-atomic Ru sites (w-SA-Ru/Ni(OH)x) were synthesized via a photoreduction strategy. In such catalysts, single-atomic Ru sites are anchored to the vacancies surrounding the pits. Notably, the SA-Ru/Ni(OH)x with 0.60 wt % Ru loading (0.60-SA-Ru/Ni(OH)x) exhibits the highest catalytic performance (27.6 mmol g-1 h-1) during the photocatalytic reduction of CO2 (CO2RR). Either superfluous (0.64 wt %, 18.9 mmol g-1 h-1; 3.35 wt %, 9.4 mmol-1 h-1) or scarce (0.06 wt %, 15.8 mmol g-1 h-1; 0.29 wt %, 21.95 mmol g-1 h-1; 0.58 wt %, 23.4 mmol g-1 h-1) of Ru sites have negative effect on its catalytic properties. Density functional theory (DFT) calculations combined with experimental results revealed that CO2 can be adsorbed in the pits; single-atomic Ru sites can help with the conversion of as-adsorbed CO2 and lower the energy of *COOH formation accelerating the reaction; the excessive single-atomic Ru sites occupy vacancies that retard the completion of CO2RR.

15.
Adv Mater ; 36(25): e2401055, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38569116

ABSTRACT

Atomic metal catalysts have unique electronic, structural, and catalytic properties, which are widely used in the field of catalysis. However, designing new simple synthesis methods to fabricate atomic metal catalysts is a challenge in catalytic applications. Herein, a one-step precursor combustion strategy is presented that starts directly from precursors of metal salts, using a spontaneous combustion process convert platinum nitrate to atomic Pt sites. The atomic Pt sites with low valence are anchored in the formed interface between grains on vacancy-enriched CeO2 nanosheets. The obtained Pt/CeO2-2 catalyst exhibits much higher three-way catalytic activities at low temperatures than Pt/CeO2-C catalysts prepared using the traditional impregnation method. Density functional theory calculations show that the generated lower valent Pt atoms in the CeO2 interface promote catalytic activity through reducing the energy barrier, and lead to an overall improvement of three-way catalytic activities. This facile strategy provides new insights into the study of the properties and applications of atomic noble metal catalysts.

16.
Adv Mater ; 36(25): e2400523, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38594481

ABSTRACT

The interaction between oxygen species and metal sites of various orbitals exhibits intimate correlation with the oxygen reduction reaction (ORR) kinetics. Herein, a new approach for boosting the inherent ORR activity of atomically dispersed Fe-N-C matrix is represented by implanting Fe atomic clusters nearby. The as-prepared catalyst delivers excellent ORR activity with half-wave potentials of 0.78 and 0.90 V in acidic and alkaline solutions, respectively. The decent ORR activity can also be validated from the high-performance rechargeable Zn-air battery. The experiments and density functional theory calculations reveal that the electron spin-state of monodispersed Fe active sites is transferred from the low spin (LS, t2g 6 eg 0) to the medium spin (MS, t2g 5 eg 1) due to the involvement of Fe atomic clusters, leading to the spin electron filling in σ∗ orbit, by which it favors OH- desorption and in turn boosts the reaction kinetics of the rate-determining step. This work paves a solid way for rational design of high-performance Fe-based single atom catalysts through spin manipulation.

17.
Angew Chem Int Ed Engl ; 63(27): e202404295, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38649323

ABSTRACT

Homogeneous electrocatalysts can indirect oxidate the high overpotential substrates through single-electron transfer on the electrode surface, enabling efficient operation of organic electrosynthesis catalytic cycles. However, the problems of this chemistry still exist such as high dosage, difficult recovery, and low catalytic efficiency. Single-atom catalysts (SACs) exhibit high atom utilization and excellent catalytic activity, hold great promise in addressing the limitations of homogeneous catalysts. In view of this, we have employed Fe-SA@NC as an advanced redox mediator to try to change this situation. Fe-SA@NC was synthesized using an encapsulation-pyrolysis method, and it demonstrated remarkable performance as a redox mediator in a range of reported organic electrosynthesis reactions, and enabling the construction of various C-C/C-X bonds. Moreover, Fe-SA@NC demonstrated a great potential in exploring new synthetic method for organic electrosynthesis. We employed it to develop a new electro-oxidative ring-opening transformation of cyclopropyl amides. In this new reaction system, Fe-SA@NC showed good tolerance to drug molecules with complex structures, as well as enabling flow electrochemical syntheses and gram-scale transformations. This work highlights the great potential of SACs in organic electrosynthesis, thereby opening a new avenue in synthetic chemistry.

18.
J Am Chem Soc ; 146(15): 10847-10856, 2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38583085

ABSTRACT

Transition-metal-catalyzed carbene insertion reactions of a nitrogen-hydrogen bond have emerged as robust and versatile methods for the construction of C-N bonds. While significant progress of homogeneous catalytic metal carbene N-H insertions has been achieved, the control of chemoselectivity in the field remains challenging due to the high electrophilicity of the metal carbene intermediates. Herein, we present an efficient strategy for the synthesis of a rhodium single-atom-site catalyst (Rh-SA) that incorporates a Rh atom surrounded by three nitrogen atoms and one phosphorus atom doped in a carbon support. This Rh-SA catalyst, with a catalyst loading of only 0.15 mol %, exhibited exceptional catalytic performance for heterogeneous carbene insertion with various anilines and heteroaryl amines in combination with diazo esters. Importantly, the heterogeneous catalyst selectively transformed aniline derivatives bearing multiple nucleophilic moieties into single N-H insertion isomers, while the popular homogeneous Rh2(OAc)4 catalyst produced a mixture of overfunctionalized side products. Additionally, similar selectivities for N-H bond insertion with a set of stereoelectronically diverse diazo esters were obtained, highlighting the general applicability of this heterogeneous catalysis approach. On the basis of density functional theory calculations, the observed selectivity of the Rh-SA catalyst was attributed to the insertion barriers and the accelerated proton transfer assisted by the phosphorus atom in the support. Overall, this investigation of heterogeneous metal-catalyzed carbene insertion underscores the potential of single-atom-site catalysis as a powerful and complementary tool in organic synthesis.

19.
Small ; : e2400618, 2024 Apr 21.
Article in English | MEDLINE | ID: mdl-38644234

ABSTRACT

There are few reports on lanthanide single atom modified catalysts, as the role of the 4f levels in photocatalysis is difficult to explain clearly. Here, the synergistic effect of 4f levels of Nd and heterostructures is studied by combining steady-state, transient, and ultrafast spectral analysis techniques with DFT theoretical calculations based on the construction of Nd single atom modified black phosphorus/g-C3N4 (BP/CN) heterojunctions. As expected, the generation rates of CO and CH4 of the optimized heterostructure are 7.44 and 6.85 times higher than those of CN, and 8.43 and 9.65 times higher than those of BP, respectively. The Nd single atoms can not only cause surface reconstruction and regulate the active sites of BP, but also accelerate charge separation and transfer, further suppressing the recombination of electron-hole pairs. The electrons can transfer from g-C3N4:Nd to BP:Nd, with a transfer time of ≈11.4 ps, while the radiation recombination time of electron-hole pairs of g-C3N4 is ≈26.13 µs, indicating that the construction of heterojunctions promotes charge transfer. The 2P1/2/2G9/2/4G7/2/2H11/2/4F7/2→4I9/2 emissions from Nd3+ can also be absorbed by heterostructures, which improves the utilization of light. The energy change of the key rate measurement step CO2 *→COOH* decreases through Nd single atom modification.

20.
Angew Chem Int Ed Engl ; 63(24): e202401943, 2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38594205

ABSTRACT

Electrochemical C-N coupling reaction based on carbon dioxide and nitrate have been emerged as a new "green synthetic strategy" for the synthesis of urea, but the catalytic efficiency is seriously restricted by the inherent scaling relations of adsorption energies of the active sites, the improvement of catalytic activity is frequently accompanied by the decrease in selectivity. Herein, a doping engineering strategy was proposed to break the scaling relationship of intermediate binding and minimize the kinetic barrier of C-N coupling. A thus designed SrCo0.39Ru0.61O3-δ catalyst achieves a urea yield rate of 1522 µg h-1 mgcat. -1 and faradic efficiency of 34.1 % at -0.7 V versus reversible hydrogen electrode. A series of characterizations revealed that Co doping not only induces lattice distortion but also creates rich oxygen vacancies (OV) in the SrRuO3. The oxygen vacancies weaken the adsorption of *CO and *NH2 intermediates on the Co and Ru sites respectively, and the strain effects over the Co-Ru dual sites promoting the occurrence of C-N coupling of the two monomers instead of selective hydrogenating to form by-products. This work presents an insight into molecular coupling reactions towards urea synthesis via the doping engineering on SrRuO3.

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