Dimethylamine Borane Research Articles

Pd/PVP‐ Catalyzed Formylation of Amines and Nitroarenes to N‐Formamides with CO2 and Dimethylamine Borane: The Influence of CO2 on the Formation of Azoxyarenes

AbstractThe reactivity of dimethylamine borane (DMAB) towards amines and nitroarenes was investigated in the presence of the CO2 and Pd/PVP (PVP=polyvinylpyrrolidone) nanocatalyst. The formation of borane formate, Me2NH.BH2(OCHO), by the insertion of CO2 into the B−H bond was evidenced by NMR. The reaction of DMAB with CO2 also produced a second product, DMF, formed via self‐formylation. In the presence of aromatic or aliphatic amines corresponding N‐formamides were formed efficiently. Under the same conditions nitroarenes were hydrogenated to anilines or to azoxyarenes in the absence of CO2. In both reactions very high TOF values, up to 30 min−1, were obtained. Applying a higher excess of DMAB enabled the transformation of nitroarenes to N‐formamides. The Pd/PVP catalyst was used in 7 consecutive cycles of N‐methylaniline formylation with excellent selectivity and a total TON equal to 4700.

Unraveling the Metal–Ligand Cooperativity in a Phosphine-Free Mn(II)-Catalyzed Transfer Hydrogenation of Nitriles to Primary Amines and Dehydrogenation of Dimethylamine Borane

Unraveling the Metal–Ligand Cooperativity in a Phosphine-Free Mn(II)-Catalyzed Transfer Hydrogenation of Nitriles to Primary Amines and Dehydrogenation of Dimethylamine Borane

Half-Sandwich Iminophosphonamide Rhodium Complexes as Highly Efficient Catalysts for Dehydrogenation of Dimethylamine-Borane

The dehydrogenation of dimethylamine-borane (DMAB) catalyzed by the iminophosphonamide rhodium(III) complexes [Cp*RhCl{Ph2P(N–p-Tol)(NR)}] (Iа, R = p-Tol; Ib, R = Me) in situ formed fulvene [(η4-C5Me4CH2)Rh(NPN)] (IIa, IIb) and diene [(η4-C5Me5H)Rh(NPN)] (IIIa, IIIb) rhodium(I) derivatives is studied. Catalysts IIIa and IIIb turn out to be the most active and demonstrate a TOF activity of 110 (IIIа) and 540 h–1 (IIIb) at 40°С in toluene. The activity decreases significantly in more polar and coordinating THF. At the same time, the rate of DMAB dehydrogenation by complexes Iа and Ib is lower by 10–30 times, and fulvene complexes Iа and Ib are rapidly deactivated after the active initial period (20% conversion). The kinetic studies show that the reaction has the first order with respect to the substrate and catalyst. The model 11В NMR experiments confirm that the reaction proceeds via the intermediate formation of a monomer Me2N=BH2, which rapidly dimerizes to (Me2N–BH2)2. The mechanism of DMAB dehydrogenation with the formation of unstable hydride intermediate [Cp*RhH{Ph2P(N–p-Tol)(NR)}] (IVa, IVb) is proposed on the basis of the preliminarily 31Р NMR results and published data.

Efficient Hydrogen Evolution from Dimethylamine Borane, Ammonia Borane and Sodium Borohydride Catalyzed by Ruthenium and Platinum Nanoparticles Stabilized by an Amine Modified Polymer Immobilized Ionic Liquid: a Comparative Study

Platinum and ruthenium nanoparticles stabilised by an amine modified polymer immobilised ionic liquid (MNP@NH2-PEGPIILS, M = Pt, Ru) catalyse the hydrolytic liberation of hydrogen from dimethylamine borane (DMAB), ammonia borane (AB) and NaBH4 under mild conditions. While RuNP@NH2-PEGPIILS and PtNP@NH2-PEGPIILS catalyse the hydrolytic evolution of hydrogen from NaBH4 with comparable initial TOFs of 6,250 molesH2.molcat−1.h−1 and 5,900 molesH2.molcat−1.h−1, respectively, based on the total metal content, RuNP@NH2-PEGPIILS is a markedly more efficient catalyst for the dehydrogenation of DMAB and AB than its platinum counterpart, as RuNP@NH2-PEGPIILS gave initial TOFs of 8,300 molesH2.molcat−1.h−1 and 21,200 molesH2.molcat−1.h−1, respectively, compared with 3,050 molesH2.molcat−1.h−1 and 8,500 molesH2.molcat−1.h−1, respectively, for PtNP@NH2-PEGPIILS. Gratifyingly, for each substrate tested RuNP@NH2-PEGPIILS and PtNP@NH2-PEGPIILS were markedly more active than commercial 5wt % Ru/C and 5wt% Pt/C, respectively. The apparent activation energies of 55.7 kJ mol−1 and 27.9 kJ mol−1 for the catalytic hydrolysis of DMAB and AB, respectively, with RuNP@NH2-PEGPIILS are significantly lower than the respective activation energies of 74.6 kJ mol−1 and 35.7 kJ mol−1 for its platinum counterpart, commensurate with the markedly higher initial rates obtained with the RuNPs. In comparison, the apparent activation energies of 44.1 kJ mol−1 and 46.5 kJ mol−1, for the hydrolysis NaBH4 reflect the similar initial TOFs obtained for both catalysts. The difference in apparent activation energies for the hydrolysis of DMAB compared with AB also reflect the higher rates of hydrolysis for the latter. Stability and reuse studies revealed that RuNP@NH2-PEGPIILS recycled efficiently as high conversions for the hydrolysis of DMAB were maintained across five runs with the catalyst retaining 97% of its activity.Graphical

Insight into the MOtBu (M=Na, K)-Mediated Dehydrogenation of Dimethylamine-Borane and Transfer Hydrogenation of Nitriles to Primary Amines.

Selective synthesis of primary amines from nitriles is challenging in synthetic chemistry due to the possible en-route generation of various amines and imines. Herein, we report a practical and operationally simple MOtBu-mediated (M=Na, K) transfer hydrogenation of nitriles to the corresponding primary amines with a relatively unexplored sacrificial hydrogen source (dimethylamine borane). The strategy encompasses a broad substrate scope under transition metal-free conditions and does not require any solvent. The mechanistic investigation was performed with the aid of control experiments and spectroscopic studies. The GC analysis of the reaction mixture exhibited the evolution of the H2 gas. Additionally, detailed computational calculations were undertaken to shed light on the possible intermediates and transition states involved during the present protocol.

Electrodeposited Ni–Co–B coatings: Preparation and evaluation of its wear resistance

Ni–Co–B coating was electrodeposited in sulfate bath with dimethylamine borane (DMAB) as reducing agent. The experiment explored the effect of DMAB concentration (CDMAB, 1–10 g/L), current density (Jk, 2–8 A/dm2), bath temperature (Tbath, 30–60 °C) on the coating morphology and hardness, and determined the best parameters: CDMAB = 8 g/L, Tbath = 60 °C, Jk = 4 A/dm2. The average hardness of the crack-free coating is 818 HV, and the B content is about 2 wt%. In order to develop a stress-relieving heat treatment scheme, the effects of heat treatment temperatures (100–500 °C) and holding times (1.5 h and 3 h) on the hardness of Ni–Co–B coating were studied. The highest hardness (1130 HV) is obtained at 350 °C for 1.5 h. The heat-treated Ni–Co–B coating was characterized by XRD, SEM and EPMA, and the second phase Ni3B was detected. In addition, the wear resistance and wear mechanism of the coating at room temperature and high temperature (300 °C) were studied. The results show that the wear volume of Ni–Co–B coating is reduced by more than 55% compared with Ni–Co coating. In general, Ni–Co–B coating can be used as an alternative to Ni–Co wear-resistant coating.

Selective Partial Reduction of Nitroarenes to the Hydrazoarene Catalyzed by Amine‐Modified Ordered Mesoporous Silica Immobilized Ionic Liquid (OMSIIL) Stabilised RuNPs

AbstractRuthenium nanoparticles stabilised by an amine‐modified Ordered Mesoporous Silica Immobilized Ionic Liquid (OMSIIL) are efficient catalysts for the partial reduction of nitrobenzene to hydrazobenzene with 100 % selectivity as well as the complete reduction to aniline. High selectivity for the partial reduction of nitrobenzene to hydrazobenzene was obtained when the reaction was conducted in ethanol with 0.5 mol% catalyst and NaBH4 as the hydrogen donor whereas aniline was obtained as the sole product in water when dimethylamine borane (DMAB) was used as the hydrogen donor. Interestingly, while a range of electron poor nitroarenes were reduced to the corresponding hydrazoarene with high selectivities and good conversions, nitroarenes substituted with electron donating groups resulted in complete reduction to the aniline. Composition‐time profiles suggest that reductions conducted in ethanol with sodium borohydride occur via the condensation pathway while those conducted in water using dimethylamine borane as the hydrogen source may well go via the direct pathway. This is the first example of the selective reduction of nitrobenzene to hydrazobenzene using a ruthenium nanoparticle‐based catalyst and the initial TOF of 320 mol nitrobenzene converted mol Ru−1 h−1 for the partial reduction of nitrobenzene to hydrazobenzene is markedly higher than previous literature reports. A study of the catalyst performance as a function of the surface modification revealed that each component has a direct and dramatic effect on the efficacy as RuNPs stabilised by COK‐12 modified with imidazolium‐based ionic liquid and a primary amine gave the highest conversion while selective removal of either component or replacement of the primary amine with a tertiary amine resulted in a marked reduction in efficiency.

Local coordination and electronic interactions of Pd/MXene via dual‐atom codoping with superior durability for efficient electrocatalytic ethanol oxidation

AbstractCatalyst design relies heavily on electronic metal‐support interactions, but the metal‐support interface with an uncontrollable electronic or coordination environment makes it challenging. Herein, we outline a promising approach for the rational design of catalysts involving heteroatoms as anchors for Pd nanoparticles for ethanol oxidation reaction (EOR) catalysis. The doped B and N atoms from dimethylamine borane (DB) occupy the position of the Ti3C2 lattice to anchor the supported Pd nanoparticles. The electrons transfer from the support to B atoms, and then to the metal Pd to form a stable electronic center. A strong electronic interaction can be produced and the d‐band center can be shifted down, driving Pd into the dominant metallic state and making Pd nanoparticles deposit uniformly on the support. As‐obtained Pd/DB–Ti3C2 exhibits superior durability to its counterpart (∼14.6% retention) with 91.1% retention after 2000 cycles, placing it among the top single metal anodic catalysts. Further, in situ Raman and density functional theory computations confirm that Pd/DB–Ti3C2 is capable of dehydrogenating ethanol at low reaction energies.

Conformal cobalt nanoshell deposition on nanoporous gold: A candidate for selective phosphate sensing

Conformal deposition of a Co nanoshell of tailorable thickness (1.5–7.1 nm) on the internal surfaces of nanoporous gold (NPG) was achieved by adapting conventional electroless deposition conditions to circumvent sheath-only deposition on its external surface. Confining electroless deposition onto the ligaments of NPG is challenging as it demands mass transport through the porous network with non-homogeneous deposition likely due to concurrent depletion of the species to be deposited. Spatially-controlled Co electroless deposition into NPG's pores required the sequential addition of dimethylamine borane (DMAB) as reducing agent and an ultra-low concentration of Co ions. DMAB is drawn into the hydrophilic serpentine pores of NPG in a pre-immersion step with temperature elevation prior to addition of Co ions to yield Co@NPG composite. Deposition at planar gold under these conditions was not achieved, emphasising NPG's heightened intrinsic catalytic activity. XPS revealed the presence of cobalt oxide in the nanoshell. Preliminary exploration of oxidized Co@NPG nanocomposite as a potentiometric phosphate sensor revealed a linear dynamic range of 0.10–500 ppm. The facile, exclusively liquid-phase non-conventional electroless deposition approach unveils a new design strategy for a diverse range of core-shell nanoporous catalysts as prospective electrodes in fuel cells, energy conversion devices and sensors.

Flexible, foldable and transparent SERS film with high sensitivity and signal homogeneity via silver ion exchange and in-situ reduction

The adhesion between metal plasma and substrate was the key of surface-enhanced Raman scattering (SERS) technology. The preparation of ideal SERS substrate with multiple advantages such as high sensitivity and good signal reproducibility was still the focus of research. A flexible foldable and transparent fluorinated polyimide/silver NPs (FPI@Ag) SERS film was fabricated by the ion exchange and in-situ reduction method in this work. The effects of KOH hydrolysis time, AgNO3 ion exchange time and concentration, the type and concentration of reducing agents on the SERS performance of the FPI@Ag film were systematically discussed. As a result, the hydrolysis time of KOH affected the thickness of the metallic silver layer, the concentration of AgNO3 affected the size and spacing of Ag NPs, and the Raman signal of was remarkably enhanced when borane dimethylamine complex (DMAB) was used as reducing agent. When the detection limit of 4-Aminothiophenol was as low as 1 × 10−11 mol·L−1, the obvious Raman characteristic peak still appeared. The enhancement factor (EF) was up to 9.4 × 107. The linear quantification range was achieved in the range from 10−3–10−11 mol·L−1, R2 = 0.9987. In addition, we also performed multi-cycle bending and torsion test on the FPI@Ag film, and obtained stable Raman signals. The prepared FPI@Ag film can be attached to the surface of uneven samples, which can be used for on-site Raman detection and analysis.

When Pt nanoparticles meet oxygen-deficient Co3O4: Enabling superior performance towards on-demand hydrogen generation from hydrolytic dehydrogenation of dimethylamine borane

The regulation of the metal-support interaction in heterogeneous catalysts can promote the activation of reactants, which is beneficial for the hydrolytic dehydrogenation reaction. Herein, the hydrolytic dehydrogenation of dimethylamine borane (DMAB) is systematically studied on the oxygen vacancy (Ov) enriched Pt-Co3O4 heterogeneous catalyst with the metal-support interaction. It is found that the metallic Pt site facilitates the adsorption of DMAB molecules and the Ov on Co3O4 support as an electron-rich center cooperates with the adjacent Pt site to dissociate water molecules. The in situ Raman and attenuated total reflectance (ATR)-Fourier transform infrared (FTIR) spectroscopy reveal the effective activation and cleavage of the O-H in water and the B-H in DMAB over the Pt-Co3O4 catalyst. The optimal Pt-Co3O4 catalyst exhibits the extraordinary activity for the catalytic hydrolysis of DMAB at 303 K, delivering a high specific hydrogen generation rate (64063 mL min−1 gpt−1) and a competitive turnover frequency (TOF, 23880 molH2 molPt−1 h−1). This performance outperforms most of the reported heterogeneous catalysts for DMAB dehydrogenation. More importantly, the Pt-Co3O4 catalyst achieves the desirable on-demand hydrogen production by using special chemical switches. This finding provides the fundamental understanding of metal-oxide systems with the collaborative interfacial catalysis for boosting DMAB dehydrogenation.

Nanotitania supported ruthenium(0) nanoparticles as active catalyst for releasing hydrogen from dimethylamine borane

We reports the ex situ preparation of nanotitania supported ruthenium(0) nanoparticles (NPs) and their catalytic testing in dehydrogenation of dimethylamine borane (DMAB) in toluene solvent. Ru0/TiO2 NPs are prepared following a 2-step process: Ru3+ ions are first impregnated from the aqueous solution on titania nanopowder and then, reduced by aqueous solution of sodium borohydride. The prepared Ru0/TiO2 NPs are dried, bottled under inert N2 gas atmosphere, and used for characterization by XRD (X-ray powder diffraction), TEM (transmission electron microscopy), ICP-OES (inductively coupled plasma optical emission spectroscopy) and XPS (X-ray photoelectron spectroscopy). Ru0/TiO2 NPs with various Ru loadings are tested as catalysts in hydrogen generation from DMAB and the Ru0/TiO2 (0.48% wt. Ru) with an average diameter of 6.7 ± 1.3 nm is found to have the highest initial turnover frequency value of 1700 h−1 for the release of 1.0 mol H2 per mole of DMAB at 60 °C. Results of the recyclability test indicate quite high durability of Ru0/TiO2 NPs in dehydrogenation of DMAB.

Inkjet printing electroless copper plating on aluminum nitride substrate

Aluminum nitride (AlN) as a ceramic substrate with high thermal conductivity and mechanic strength is highly desired for high-powder density electrode devices. However, precisely metalating of AlN in an environmental friendly way is still challenging. Here, we develop a inkjet printing electroless plating technology for fabricating cupper electrode on AlN substrate. The copper ink prepared by CuSO4·5 H2O is firstly inkjet printed on AlN substrate followed reduced by a dimethylamine borane solution to form a copper seed. The AlN substrate with the copper seed layer was immersed into the formaldehyde-free environment-friendly electroless plating solution to deposit the copper layer. The prepared copper electrode demonstrated a smooth surface with robust tangential peel strength reaches 302.67 N·cm−1 and excellent conductivity to 8.70 μΩ cm. Furthermore, AlN substrate after 8 h electroless copper plating has excellent heat dissipation performance. Therefore, the inkjet printing electroless plating technology provide a promising route for scalable and precise metalating the ceramic substrates.

Mechanism, Kinetics and Simulation of Electrocatalytic Oxidation of Dimethylamine Borane (DMAB) on Electroless Gold

Dimethylamine borane ((CH3)2NHBH3) or DMAB, is broadly used as a reducing agent in electroless autocatalytic platings like gold and nickel-boron, hydrogen storage, and reductive amination. However, the mechanism of its DMAB oxidation procedure remains unclear. This project is based on the hypothesis that a multi-step electron transfer mechanism exists for oxidizing the reducing agent DMAB on gold in alkaline media. According to this mechanism, the active species produced when DMAB is used at high hydroxide content is the BH3OH-. This species is created through a series of irreversible electrochemical oxidation producing the following intermediates BH2(OH)2-, BH(OH)3- and B(OH)4-, which is the final product. Multiple electrochemical methods have been used to uncover the properties of DMAB oxidation progress and verify above-mentioned hypothesis. Electrochemical Impedance Spectroscopy (EIS) was used to test the uncompensated resistance between the working electrode and reference electrode and calibrated in the following experiments: Cyclic voltammetry (CV) showed that DMAB in hydroxide electrolytes have three half-wave potentials with E_(1/2) of -0.778, -0.174 and 0.248 V. Kinetic current values obtained from the Koutecky-Levich plot decreased with temperature with -4.065, -3.62 and -1.45 mA/cm2 at 25°C, 41°C and 52°C, respectively. Rotating Disk Electrode (RDE) and Chronoamperometry (CA) were used to determine the Diffusion Coefficient of BH3(OH)-; BH2(OH)2- and BH(OH)3- 1.38E-05, 3.31E-05 and 1.01E-04, respectively. Tafel analysis was used in obtaining the transfer coefficient, whereas Klingler and Kochi’s method evaluated the constant. These kinetic parameters were used in KISSA-1D software to simulate the CVs. Gas Chromatography with Mass Spectrometry (GC/MS) was used to verify the existence of B(OH)4- and a peak at m/z 78.8 was recorded. All of this provided evidence that the three intermediates are involved in the proposed mechanism. In the future, simulated and experimental approaches will be investigated for other amine boranes compounds such as Sodium cyanoborohydride (NaBH3CN), Sodium triacetoxyborohydride (NaBH(O2CCH3)3), and Sodium borohydride (NaBH4). This work will have far-reaching consequences in enhancing the practical applications of gold and nickel in microelectronics and fuel cells.

The effect of chelators on additives in the surface characterization and electrochemical properties of an eco-friendly electroless copper nano deposition

We represent the results of a study on as the chelators used in the environmentally friendly electroless deposition bath changed depending on the amounts of hydroxides were present. The baths were prepared using polyhydroxides, glycerol and sorbitol, as chelators with copper methanesulfonate as the metal ion. Dimethylamine borane (DMAB) was used as the reducing agent with N-methylthiourea and cytosine, as additives in both the glycerol and sorbitol contained baths. Potassium hydroxide was used as the pH adjuster, with glycerol and sorbitol baths maintained at a pH of 11.50 and 10.75 respectively at a room temperature of 28 ± 2 °C. XRD, SEM, AFM, cyclic voltammetry studies, Tafel and Impedance studies, as well as additional methods, were employed to monitor and record the surface, structural, and electrochemical characteristics of the deposits and bath. The reports of the study gave interesting results, which clearly the effect of chelators on additives in the nano deposition of copper in an electroless deposition bath.

Facile synthesis of Ag/Co3O4 nanocubes for on-demand H2 evolution upon dimethylamine borane hydrolysis

The crystalline structure and morphology of heterogeneous catalysts plays an increasingly important role in its ultimate catalytic activity. Herein, we have synthesized and compared the catalytic activities of Ag/Co3O4 cubes (Ag/Co3O4-c), Ag/Co3O4 octahedron (Ag/Co3O4-o) and Ag/Co3O4 truncated octahedron (Ag/Co3O4-t), via immobilization of Ag nanoparticles onto the surface of Co3O4-c/o/t, in dimethylamine borane (DB) hydrolysis for on-demand H2 evolution at 30 °C. In particular, Co3O4-c, Co3O4-o and Co3O4-t were enclosed with six {100}, six {111} resp. the mixture of six {100} and eight {111} exposing facets. Ag/Co3O4-c (1373 mol (H2)·molAg−1·h−1) exhibited more efficient catalytic activity than those of Ag/Co3O4-t (1172 mol (H2)·molAg−1·h−1) and Ag/Co3O4-o (804 mol (H2)·molAg−1·h−1) in DB hydrolysis. The (Density Functional Theory) DFT result illustrated that the Eads of Ag/Co3O4 {100} facets (−2.07 eV) was much lower than that of Ag/Co3O4 {111} facets (−1.72 eV), suggesting Ag/Co3O4 {100} facets is favor of DB adsorption, which is in consistent with our above experimental result. More interestingly, “on–off” control of on-demand H2 evolution upon DB hydrolysis over Ag/Co3O4-c was successfully achieved by the Zn2+/EDTA-2Na system, for effectively and safely producing, transporting and storing hydrogen in the future.

Eco-Friendly Electroless Template Synthesis of Cu-Based Composite Track-Etched Membranes for Sorption Removal of Lead(II) Ions

This paper reports the synthesis of composite track-etched membranes (TeMs) modified with electrolessly deposited copper microtubules using copper deposition baths based on environmentally friendly and non-toxic reducing agents (ascorbic acid (Asc), glyoxylic acid (Gly), and dimethylamine borane (DMAB)), and comparative testing of their lead(II) ion removal capacity via batch adsorption experiments. The structure and composition of the composites were investigated by X-ray diffraction technique and scanning electron and atomic force microscopies. The optimal conditions for copper electroless plating were determined. The adsorption kinetics followed a pseudo-second-order kinetic model, which indicates that adsorption is controlled by the chemisorption process. A comparative study was conducted on the applicability of the Langmuir, Freundlich, and Dubinin-Radushkevich adsorption models to define the equilibrium isotherms and the isotherm constants for the prepared composite TeMs. Based on the regression coefficients R2, it has been shown that the Freundlich model better describes the experimental data of the composite TeMs on the adsorption of lead(II) ions.

Amino‐Modified Polymer Immobilized Ionic Liquid Stabilized Ruthenium Nanoparticles: Efficient and Selective Catalysts for the Partial and Complete Reduction of Quinolines

AbstractRuNPs stabilised by amino‐decorated imidazolium‐based polymer immobilized ionic liquids catalyse the dimethylamine borane mediated reduction of quinolines to 1,2‐dihydroquinoline (DHQ) and 1,2,3,4‐tetrahydroquinoline (THQ). Partial reduction of 3‐substituted quinolines to the corresponding 1,2‐dihydroquinoline was achieved with 100 % selectivity in toluene under mild conditions. This is the first report of the selective partial reduction of 3‐substituted quinolines to the corresponding 1,2‐dihydroquinolines with a heterogeneous nanoparticle‐based catalyst. A wide range of substituted quinolines have also been reduced to the corresponding 1,2,3,4‐tetrahydroquinoline with high selectivity and good yields by adjusting the reaction time. The 1,2‐dihydroquinolines readily release dihydrogen in toluene at 60 °C in the absence of catalyst with no evidence for disproportionation and as such are potential organo‐hydride reagents. The initial TOF of 610 mol quinoline converted mol Ru−1 h−1 for the reduction of quinoline is among the highest to be reported for a metal nanoparticle‐based catalyst and the conversion of 96 % obtained after 4 h at 65 °C is significantly higher than its platinum nanoparticle counterpart PtNP@NH2‐PEGPIILS as well as 5 wt/% Ru/C, which only reached 9 % and 11 % conversion, respectively, at the same time. Hot filtration experiments showed that the active species was heterogeneous.

Electronic regulation over Pd nanoparticles: One-pot synthesis of B, N Co-doping MXene-supported Pd catalyst for efficient ethanol oxidation

Multi-element doping support is considered an effective method to improve the electrocatalytic performance of catalysts, but there is a lack of simple and mild methods to prepare catalysts. In this article, dimethylamine borane is used as a heteroatom dopant and a metal-reducing agent at the same time, realizing the co-doping of B and N atoms and the deposition of metal Pd on Ti3C2 through a rapid, one-step hydrothermal method. By exploring the electrocatalytic properties of ethanol oxidation, the Pd/DMAB-Ti3C2 exhibits much higher electrochemically active surface areas, ethanol-oxidated current densities, and electrochemical stability than those of the single-doped and undoped catalysts. And the current densities after 350 redox cycles of Pd/DMAB-Ti3C2 can retain 74.6 % of the maximum capacity. Such different properties can be attributed to the synergy of B and N species in the Ti3C2 introduced by dimethylamine borane, which significantly affects the electron transfer and d band center of supported metal Pd, thus facilitating the progress of the EOR along a favorable pathway. This work provides a new insight into synthesizing the high-performance B and N co-doped supported metal catalyst through a rapid one-step synthesis.

Solventless Dimethylamine Borane Dehydrogenation in the Presence of Transition Metal(0) Nanoparticles Loaded on Cellulose

AbstractHerein, the results of in‐situ synthesis of four different metal(0) nanoparticles (Pd, Cu, Ru, and Ni) loaded on the surface of cellulose (MNPs@Cellulose) separately and their catalytic use in the solventless dimethylamine‐borane (DMAB) dehydrogenation at 35.0±0.1 °C are reported. Based on the detailed kinetic studies on the solventless DMAB dehydrogenation catalyzed using MNPs@Cellulose, the following results were obtained: (i) Optimum metal loading percentage on the surface of cellulose was determined for Pd@Cellulose to be 4.0 wt.%Pd (152.39 h−1), Ni@Cellulose to be 3.0 wt.%Ni (59.09 h−1), Cu@Cellulose to be 3.0 wt.%Cu (55.45 h−1) and Ru@Cellulose to be 4.0 wt.%Ru (46.06 h−1) and by determining total turnover frequency values in average 10th minutes (TOF10), which provided the highest catalytic activity. (ii) The optimum amount of cellulose for each metal was found to be 50.0 mg for Pd, Cu, and Ru, and 40.0 mg for Ni. (iii) The Arrhenius activation energies were determined for each metal nanoparticles and calculated to be 69±2, 34±2, 35±2 and 42±2 kj.mol−1 for Pd@Cellulose, Ni@Cellulose, Cu@Cellulose, and Ru@Cellulose, respectively.