Efficient and Selective Aerobic Alcohol Oxidation Catalyzed by Copper(II)/2,2,6,6,‐Tetramethylpiperidine‐1‐oxyl at Room Temperature

A simple and efficient copper(II)/2,2,6,6,‐tetramethylpiperidine‐1‐oxyl (TEMPO)‐catalyzed aerobic oxidation of both primary and secondary benzylic, allylic, and aliphatic alcohols to their corresponding aldehydes and ketones at room temperature using the copper(II) complex [Cu(μ‐Cl)(Cl)(phen)]₂ as the Cu(II) source is reported. The conversion of both electron‐rich and electron‐neutral benzyl alcohols is smooth and faster than those of electron‐deficient ones. The chemoselectivity of a primary benzyl alcohol over the secondary alcohol is also observed. Alcohols regarded as difficult substrates for oxidation due to their coordinating ability with transition metal catalyst such as 4‐(methylthio)benzyl alcohol and 3‐pyridinemethanol are also oxidized easily. In addition, a lignin model alcohol is oxidized to the corresponding aldehyde in excellent yield. Conversions of benzylic and allylic alcohols are faster as compared to those of aliphatic alcohols in accordance with their C_α H bond strengths. A plausible mechanism of the TEMPO‐based catalytic cycle is proposed.     

Hydroxylamine as a Source for Nitric Oxide in Metal‐Free 2,2,6,6‐ Tetramethylpiperidine N‐Oxyl Radical (TEMPO) Catalyzed Aerobic Oxidation of Alcohols

The communication reports on the metal‐free 2,2,6,6‐tetramethylpiperidine N‐oxyl radical (TEMPO) catalyzed aerobic oxidation of various alcohols to aldehydes and ketones. A novel catalyst system that uses 1–4 mol% of TEMPO in combination with 4–6 mol% of aqueous hydroxylamine is introduced. No other additives are necessary and corrosive by‐products are not formed during oxidation. Nitric oxide which is important for the catalytic cycle is generated in situ by reaction of the hydroxylamine with TEMPO. A catalytic cycle for the overall oxidation process is suggested.     

Activation of Dioxygen by Cobaloxime and Nitric Oxide for Efficient TEMPO‐Catalyzed Oxidation of Alcohols

The aerobic oxidation of alcohols to their corresponding carbonyl compounds could be efficiently accomplished by using the combination of cobalt nitrate, dimethylglyoxime and 2,2,6,6‐tetramethylpiperidine 1‐oxyl (TEMPO) as a novel catalytic system, and various alcohols including primary and secondary benzylic, allylic and aliphatic alcohols could be quantitatively converted to the corresponding aldehydes or ketones at 70 °C under 0.4 MPa dioxygen pressure in dichloromethane. During the oxidation, the in situ generated cobaloxime and nitric oxide (NO) were responsible for the activation of dioxygen, respectively, thereby, two concerted catalytic routes exist: cobaloxime‐activating‐dioxygen TEMPO‐catalyzed and NO‐activating‐dioxygen TEMPO‐catalyzed aerobic oxidation of alcohols.     

Galvanic deposition of silver on 80‐μm‐Cu‐fiber for gas‐phase oxidation of alcohols

Microstructured Ag‐based catalysts were developed by galvanically depositing Ag onto 80‐μm‐Cu‐fibers for the gas‐phase oxidation of alcohols. By taking advantages including large voidage, open porous structure and high heat/mass transfer, as‐made catalysts provided a nice combination of high activity/selectivity and enhanced heat transfer. The best catalyst was Ag‐10/80‐Cu‐fiber‐400 (Ag‐loading: 10 wt%; Cu‐fiber pretreated at 400 °C in air), being effective for oxidizing acyclic, benzylic and polynary alcohols. For benzyl alcohol, conversion of 94% was achieved with 99% selectivity to benzaldehyde at 300 °C using a high WHSV of 20 h^?1. Computational fluid dynamics (CFD) calculation and experimental result illustrated significant enhancement of the heat transfer. The temperature difference from reactor wall to central line was about 10–20 °C for the Ag‐10/80‐Cu‐fiber‐400, much lower than that of 100–110 °C for the Ag‐10‐Cu‐2/Al₂O₃ at equivalent conversion and selectivity. Synergistic interaction between Cu₂O and Ag was discussed, being assignable to the activity improvement. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1045–1053, 2014     

Aerobic Oxidation of Benzylic Alcohols in Water by 2,2,6,6‐Tetramethylpiperidine‐1‐oxyl (TEMPO)/Copper(II) 2‐N‐Arylpyrrolecarbaldimino Complexes

Novel copper(II) 2‐N‐arylpyrrolecarbaldimine‐based catalysts for the aerobic oxidation of benzylic alcohols mediated by the 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO) radical are reported. The catalytic activity for both synthesized and in situ made complexes in alkaline water solutions was studied revealing high efficiency and selectivity (according to GC selectivity always >99%) for both of these catalytic systems. For example, quantitative conversion of benzyl alcohol to benzaldehyde can be achieved with the in situ prepared bis[2‐N‐(4‐fluorophenyl)‐pyrrolylcarbaldimide]copper(II) catalysts in 2 h with atmospheric pressure of O₂ at 80 °C. Interestingly, these catalysts can utilize dioxygen as well as air or hydrogen peroxide as the end oxidants, producing water as the only by‐product.     

Controlled radical double ring‐opening polymerization of 2‐methylene‐1,4,6‐trioxaspiro[4,4]nonane

Controlled radical double ring‐opening polymerization of 2‐methylene‐1,4,6‐trioxaspiro[4,4]nonane (MTN) has been achieved with tert‐butyl perbenzoate (TBPB) as initiator in the presence of 2,2,6,6‐tetramethyl‐1‐piperidinyloxy free radical (TEMPO) at 125 °C. The molecular weight polydispersity of the polymers is obviously lower than that of polymers obtained by conventional procedures. As the [TEMPO]/[TBPB] molar ratio increased, the polydispersity decreased and a polydisperty as low as 1.2 was obtained at high TEMPO concentration. With the conversion of the monomer increasing, the molecular weight of the polymers turned higher and a linear relationship between the M_w and the monomer conversion was observed. The monomer conversion, however, did not exceed 30 %. © 2000 Society of Chemical Industry     

Preparation and kinetic analysis of PS‐b‐PBA block copolymer by 4‐oxo‐TEMPO capped polystyrene macroinitiators

Polystyrene‐block‐poly(n‐butyl acrylate) block copolymers were prepared from 4‐oxo‐2,2,6,6‐tetramethylpiperidinooxy (4‐oxo‐TEMPO) capped polystyrene macroinitiators at a high temperature, 165°C. It was found that the number‐average molecular weight of PBA chains in block copolymers could reach above 10,000 rapidly at early stage of polymerization with a narrow polydispersity index of 1.2–1.4, but after that, the polymerization seemed to be retarded. Furthermore, according to the kinetic analysis, the concentration of 4‐oxo‐TEMPO was increased mainly by the hydrogen transfer reaction of hydroxylamine (4‐oxo‐TEMPOH) to growing radicals during polymerization. This increase in 4‐oxo‐TEMPO concentration could retard the growth of polymer chains. The rate constant of the hydrogen transfer reaction of 4‐oxo‐TEMPOH to growing radicals, k_H, estimated by the kinetic model is about 9.33 × 10⁴M^‐1s^?1 at 165°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

TEMPO‐Copper(II) Diimine‐Catalysed Oxidation of Benzylic Alcohols in Aqueous Media

In situ generated copper(II)‐diimine complexes combined with TEMPO (2,2,6,6‐tetramethylpiperidinyl‐1‐oxyl radical) were studied in the oxidation of benzylic alcohols, the focus being on enviromentally benign reaction conditions. In this respect, reactions were studied in aqueous alkaline solutions and dioxygen was used as an end oxidant. This simple catalytic system turned out to be highly efficient and selective in the oxidation of primary and secondary benzylic alcohols to their corresponding carbonyl compounds. Under optimised reaction conditions [5 mol % of TEMPO, 3 mol % of copper(II ) diimine, pH 12.6–13.5, 80 °C, 10 bar O₂] benzyl alcohol was quantitatively and selectively oxidised to benzaldehyde. According to ESI‐MS studies, coordination of TEMPO, as well as deprotonated benzyl alcohol to the parent copper‐diimine complex in aqueous solutions is feasible. Supported by these observations a plausible reaction mechanism is proposed for the oxidation reaction.     

Gold(I)‐Catalyzed Tandem Alkoxylation/Lactonization of γ‐Hydroxy‐α,β‐Acetylenic Esters

The formation of 4‐alkoxy‐2(5H)‐furanones was achieved via tandem alkoxylation/lactonization of γ‐hydroxy‐α,β‐acetylenic esters catalyzed by 2 mol% of [2,6‐bis(diisopropylphenyl)imidazol‐2‐ylidine]gold bis(trifluoromethanesulfonyl)imidate [Au(IPr)(NTf₂)]. The economic and simple procedure was applied to a series of various secondary propargylic alcohols allowing for yields of desired product of up to 95%. In addition, tertiary propargylic alcohols bearing mostly cyclic substituents were converted into the corresponding spiro derivatives. Both primary and secondary alcohols reacted with propargylic alcohols at moderate temperatures (65–80 °C) in either neat reactions or using 1,2‐dichloroethane as a reaction medium allowing for yields of 23–95%. In contrast to [Au(IPr)(NTf₂)], reactions with cationic complexes such as [2,6‐bis(diisopropylphenyl)imidazol‐2‐ylidine](acetonitrile)gold tetrafluoroborate [Au(IPr)(CH₃CN)][BF₄] or (μ‐hydroxy)bis{[2,6‐bis(diisopropylphenyl)imidazol‐2‐ylidine]gold} tetrafluoroborate or bis(trifluoromethanesulfonyl)imidate – [{Au(IPr)}₂(μ‐OH)][X] (X=BF₄, NTf₂) – mostly stop after the alkoxylation. Analysis of the intermediate proved the exclusive formation of the E‐isomer which allows for the subsequent lactonization.     

Microbial transformation of androst‐4‐ene‐3, 17‐dione by Bordetella sp. B4 CGMCC 2229

BACKGROUND: Microbial transformation of steroids has attracted widespread attention, especially the transformation of those steroids synthesized with difficulty by chemical methods. In this study, microbial transformation of androst‐4‐ene‐3, 17‐dione (AD) by Bordetella sp. B4 was investigated, and the effect of temperature on transformation was studied. RESULTS: Three metabolites were purified by preparative TLC and HPLC, and identified as androsta‐1,4‐diene‐3,17‐dione (ADD), 9α‐hydroxyandrost‐4‐ene‐3, 17‐dione (9α‐OH‐AD), and 3‐hydroxy‐9, 10‐secoandrost‐1, 3, 5‐triene‐9, 17‐dione (3‐OH‐SATD) by nuclear magnetic resonance imaging (NMR), Fourier transform infrared spectroscopy (FTIR) and mass spectroscopy (MS). It was first reported that the genus of Bordetella has the capability of AD degradation. Microbial transformation of AD was performed at 30 °C, 37 °C, 40 °C and 45 °C. The 9α‐OH‐AD yield reached a maximum within 16 h when the strain was cultivated in media with AD as sole carbon at 37 °C. Surprisingly, ADD was produced by the strain cultivated at 40 °C but not at 37 °C, which was different from previous reports. It was deduced that the alcohol dehydrogenase that catalyzed the transformation of AD to ADD may be temperature sensitive. CONCLUSION: Androst‐4‐ene‐3,17‐dione was converted into 9α‐hydroxyandrost‐4‐ene‐3, 17‐dione and other metabolites rapidly by Bordetella sp. B4. It is anticipated that the strain Bordetella sp. B4 CGMCC 2229 can be used in the steroids industry. Copyright © 2009 Society of Chemical Industry     

Nitroxide‐mediated homopolymerization and copolymerization of 2‐vinylpyridine with styrene

Homopolymerization and copolymerization of 2‐vinylpyridine (2VP) with styrene (S) at 125°C in the presence of 2,2,6,6‐tetramethyl piperidin‐1‐yloxyl (TEMPO) radicals have been studied. The homopolymerization was carried out with 2,2′‐azobis(isobutyronitrile) (AIBN) as a thermal initiator or without AIBN in the initial reaction mixture. In the copolymerization initiated with AIBN, the molar fraction of 2VP in the feed, F_2VP, varied in the range of 0.1–0.9; F_2VP = 0.65 was found to be the azeotropic composition. The linear semilogarithmic time–conversion plots demonstrated a pseudoliving nature of the polymerizations under study. The molecular weight–conversion dependences indicated the participation of side reactions, diminishing the number of TEMPO‐terminated polymer chains. The synthesized homopolymers and copolymers were characterized using size‐exclusion chromatography (SEC), nitrogen analysis, and NMR spectroscopy. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2024–2030, 2001     

Synthesis,electroluminescence, and photovoltaic cells of new vinylene‐copolymers with 4‐(anthracene‐10‐yl)‐2,6‐diphenylpyridine segments

Three new soluble vinylene‐copolymers F , C, and P that contain 4‐(anthracene‐10‐yl)‐2,6‐diphenylpyridine as common segment and fluorene, carbazole, or phenylene, respectively, as alternating segment were prepared by Heck coupling. The glass transition temperature was high for F and C (110 and 117°C), whereas was lower than 25°C for P . The polymers were stable up to ～ 300°C. They emitted blue–green light with maximum located at wavelength of 456–550 nm, which was of the order F < C < P . The photoluminescence quantum efficiency in THF solution was ～ 30% for F and P and only 5% for C . All three copolymers were used as active layers for polymer light emitting diodes (PLEDs) and organic photovoltaic cells. The double PLEDs with configuration of indium‐tin oxide (ITO)/poly(ethylenedioxythiophene (PEDOT) : poly(styrenesulfonate)(PSS)/Copolymer F , C , or P /TPBI(1,3,5‐tris(2‐N‐phenylbenzimidazolyl)benzene)/Ca/Al were fabricated. Copolymer P emitted green light with maximum brightness of 28 cd/m² and a current yield of 0.85 cd/A. Organic photovoltaics with the configuration of ITO/PEDOT : PSS/Copolymer and [6,6]‐phenyl‐C61‐butyric acid methyl ester blend (1 : 1) /Ca/Al were also fabricated. Copolymer P showed the highest power conversion efficiency of 0.034%. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Experimental Phase Diagram Determination and Thermodynamic Assessment of the CeO2‐Gd2O3‐CoO System

New phase diagram data and a thermodynamic assessment of the CeO‐Gd₂O₃‐CoO system using the CALPHAD approach are presented. This information is needed to understand the surprisingly low sintering temperature (950°C–1050°C) of CeO₂‐based materials doped with small amounts of transition metal oxide (e.g., CoO). Experimental phase equilibria between 1100°C and 1300°C are reported based on the analysis of annealed and molten samples. No isolated compound exists in the ternary. At 1300°C the Co solubility in the ternary compounds Ce_1?x?yGd_xCo_yO_2?x/2?y (fluorite) is 2.7 mol% and is less than 1 mol% in the Gd_2?xCe_xO_3+x/2 (bixbyite). The Ce solubility in the perovskite GdCoO_3?δ was found to be 1 mol%. The lowest temperature eutectic melt in the ternary has a composition of 57.2 mol% Co and 41.1 mol% Gd melting at an onset temperature of 1303 ± 5°C, which is close to the binary eutectic in the Gd₂O₃‐CoO system at 60 ± 2 mol% Co and 1348 ± 1°C.     

Oxygen‐ion conduction in scandia‐stabilized zirconia‐ceria solid electrolyte (xSc2O3–1CeO2–(99−x)ZrO2, 5 ≤ x ≤ 11)

Solid oxide fuel cells (SOFCs) operating at intermediate temperature (500°C‐700°C) provide advantages of better durability, lower cost, and wider target application market. In this work, we have studied Sc₂O₃ (5‐11 mol%) stabilized ZrO₂–CeO₂ as a potential solid electrolyte for application in IT‐SOFCs. Lower Sc₂O₃ doping range than the traditional 11 mol% Sc₂O₃‐stabilized ZrO₂ is an interesting research topic as it could potentially lead to an electrolyte with reduced oxygen vacancy ordering, lower cost, and higher mechanical strength. XRD and Raman spectroscopy was used to study the phase equilibrium in ZrO₂–CeO₂–Sc₂O₃ system and impedance spectroscopy was done to estimate the grain, grain boundary, and total ionic conductivities. Maximum for the grain and grain‐boundary conductivities as well as the tetragonal‐cubic phase boundary was found at 8‐9 Sc₂O₃ mol% in ZrO₂‐1 mol% CeO₂ system. It is suggested that the addition of 1 mol% CeO₂ in the ZrO₂ host lattice has improved the phase stability of high‐conductivity cubic and tetragonal phases at the expense of low‐conductivity t′‐ and β‐phases.     

High‐resolution thermogravimetry of poly(2,6‐dimethyl‐1,4‐phenylene oxide)

The thermal degradation and kinetics of poly(2,6‐dimethylphenylene oxide) (PPO) were studied by high‐resolution thermogravimetry. The thermogravimetry measurements were conducted at an initial heating rate of 50°C min⁻¹, resolution 4.0, and sensitivity 1.0 in both nitrogen and air from room temperature to 900°C. A two‐step degradation process was clearly revealed in air at the temperatures of 430°C and 521°C. The thermal degradation temperatures and kinetic parameters of the PPO appear to be higher in air than in nitrogen, indicative of a higher thermostability in air. The temperature, activation energy, order, and frequency factor of the thermal degradation of the PPO in nitrogen are 419°C, 100–120 kJ mol⁻¹, 0.5, and 13–17 min⁻¹, respectively. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1887–1892, 1999     

2,6‐Diamino‐4‐phenylphenol (DAPP) copolymerized polyimides: synthesis and characterization

Novel soluble copolyimides containing phenyl and hydroxyl pendant groups were synthesized from pyromellitic dianhydride (PMDA) and two diamines, 2,6‐diamino‐4‐phenylphenol (DAPP) and 4,4′‐oxydianiline (ODA), in various ratios via thermal imidization. The structures and physical properties of the copolyimides were characterized by FTIR, elemental analysis, DSC, dynamic mechanical analysis (DMA), TGA, a universal testing machine for stress–strain behaviour, and a dielectric analyzer to study the effect of DAPP on the physical properties of the modified polymers. Copolyimides containing more than 40 mol% DAPP were soluble in hot N‐methyl‐2‐pyrrolidone (NMP), dimethylacetamide (DMAc) and dimethylformamide (DMF), and possessed a high glass transition temperature (358 °C) and a high modulus (3.9 GPa). Introduction of the diamine DAPP could also reduce the dielectric constant. A segment of imide linkages could convert to benzoxazole linkages by decarboxylation at temperatures higher than 420 °C under vacuum. Although the heat‐treated polybenzoxazoles (PBOs) exhibited many good properties, they were found to be too rigid and brittle to be processable for microelectronic applications. Copyright © 2005 Society of Chemical Industry     

2,2,6,6‐Tetramethylpiperidine‐1‐oxyl‐mediated living mini‐emulsion polymerization of styrene under ambient pressure in a semi‐batch process: effect of ascorbic acid

2,2,6,6‐Tetramethylpiperidine‐1‐oxyl (TEMPO)‐mediated living mini‐emulsion polymerization of styrene with feeding of an ascorbic acid aqueous solution throughout the polymerization was performed at 90 °C under ambient pressure. The concentrations of sodium dodecylbenzenesulfonate (SDBS) and ascorbic acid were varied to study the shell polymerization mechanism of latex particles and evolution of growing chains. Interactions between SDBS and ascorbic acid and incompatibility between ascorbic acid and styrene were evident from UV‐visible analyses. High hydrophilicity of ascorbic acid in the aqueous phase was proved using a gravimetric method. Accordingly, the formation of a surface barrier on particles was proposed because of the interactions between SDBS and ascorbic acid. For higher SDBS concentration, the surface barrier on the particles was denser. Therefore, the polymerization rate decreased with increasing SDBS concentration. However, the polymerization rate increased with increasing ascorbic acid concentration. This was due to a higher consumption rate of TEMPO by ascorbic acid. Free TEMPO tended to reside in surface zones of the particles because of the surface activity between the aqueous and oil phases. The surface zones were thus the main loci where TEMPO was consumed by ascorbic acid. The estimated number‐average molecular weight (M_n) of growing chains increased in a linear fashion with conversion. This indicated that the growing chains were produced via living mini‐emulsion polymerization. For these growing chains, the estimated M_n and final polydispersity increased with increasing SDBS concentration. This was caused by a decrease in TEMPO concentration in the surface zones of particles with increasing SDBS concentration. The ‘livingness’ of polystyrene was identified by conducting bulk polymerization of chain extension. Based on the results obtained, a shell polymerization mechanism of latex particles was proposed, and living mini‐emulsion polymerization was limited to the surface zones of particles. Copyright © 2010 Society of Chemical Industry     

Rhodium‐Catalyzed Highly Regioselective Hydroformylation‐Hydrogenation of 1,2‐Allenyl‐Phosphine Oxides and ‐Phosphonates

The rhodium‐catalyzed hydroformylation‐hydrogenation of 1,2‐allenyl‐phosphine oxides and ‐phosphonates is reported in this paper. The regioselectivity was well controlled, affording only saturated linear γ‐phosphinyl aldehydes under the standard conditions: (carbonyl)tris(triphenylphosphine)‐rhodium hydride [RhH(CO)(PPh₃)₃] (3 mol%), triphenylphosphine (PPh₃) (10 mol%), carbon monoxide (CO) (2.4×10⁶ Pa), hydrogen (H₂) (subsequently charged to 4.8×10⁶ Pa), toluene, 100 °C, 24 h.     

Effective biosynthesis of poly(3‐hydoxy‐ butyrate‐co‐4‐hydroxybutyrate) with high 4‐hydroxybutyrate fractions by Wautersia eutropha in the presence of α‐amino acids

BACKGROUND: Biopolymers produced by microbes are in demand as their biodegradable and biocompatible properties make them suitable for disposable products and for potential use as biomaterials for medical applications. The effective microbial production of copolyesters of 3‐hydroxybutyrate (3HB) and 4‐hydroxybutyrate(4HB) with high molar fractions of 4HB unit by a wild‐type Wautersia eutropha H16 was investigated in culture media containing 4‐hydroxybutyric acid (4HBA) and different carbon substrates in the presence of various α‐amino acids. RESULTS: The addition of carbon sources such as glucose, fructose and acetic acid to the culture medium containing 4HBA in the presence of α‐amino acids resulted in the production of random poly(3HB‐co‐4HB) with compositions of up to 77 mol% 4HB unit, but the yields of copolyesters with 60–77 mol% 4HB units were less than 15 wt% of dried cell weights. In contrast, when carbon sources such as propionic acid and butyric acid were used as the co‐substrates of 4HBA in the presence of α‐amino acids, poly(3HB‐co‐4HB) copolyesters with compositions of 72–86 mol% 4HB were produced at maximally 47.2 wt% of dried cell weight (11.3 g L^?1) and the molar conversion yield of 4HBA to 4HB fraction in copolyesters was as high as 31.4 mol%. Further, poly(3HB‐co‐4HB) copolyesters with compositions of 93–96 mol% 4HB were isolated at up to 35.2 wt% of dried cell weights by fractionation of the above copolymers with chloroform/n‐hexane. CONCLUSION: The productivity of copolyesters with over 80 mol% 4HB fractions was as high as 0.146 g L^?1 h^?1 (3.51 g L^?1 for 24 h) by flask batch cultivation. Copyright © 2007 Society of Chemical Industry     

Carbon nanotube/graphene oxide‐added CaO‐B2O3‐SiO2 glass/Al2O3 composite as substrate for chip‐type supercapacitor

A CaO‐B₂O₃‐SiO₂ (CBS) glass/40 wt% Al₂O₃ composite sintered at 900°C exhibited a dense microstructure with a low porosity of 0.21%. This composite contained Al₂O₃ and anorthite phases, but pure glass sintered at 900°C has small quantities of wollastonite and diopside phases. This composite was measured to have a high bending strength of 323 MPa and thermal conductivity of 3.75 W/(mK). The thermal conductivity increased when the composite was annealed at 850°C after sintering at 900°C, because of the increase in the amount of the anorthite phase. 0.25 wt% graphene oxide and 0.75 wt% multi‐wall carbon nanotubes were added to the CBS/40 wt% Al₂O₃ composite to further enhance the thermal conductivity and bending strength. The specimen sintered at 900°C and subsequently annealed at 850°C exhibited a large bending strength of 420 MPa and thermal conductivity of 5.51 W/(mK), indicating that it would be a highly effective substrate for a chip‐type supercapacitor.