This study explores the controllable synthesis of CuAlO_(2) using copper hydroxide and pseudo-boehmite powders as raw materials via a simple solid-phase ball milling method,along with its catalytic performance investi...This study explores the controllable synthesis of CuAlO_(2) using copper hydroxide and pseudo-boehmite powders as raw materials via a simple solid-phase ball milling method,along with its catalytic performance investigation in methanol steam reforming(MSR).Various catalysts were prepared under different conditions,such as calcination temperature,calcination atmosphere,and heating rate.Characterization techniques including BET,XRD,XPS,SEM and H2-TPR were employed to analyze the samples.The results revealed significant effects of calcination temperature on the phase compositions,specific surface area,reduction performance,and surface properties of the CA-T catalysts.Based on the findings,a synthesis route of CuAlO_(2) via the solid-phase method was proposed,highlighting the importance of high calcination temperature,nitrogen atmosphere,and low heating rate for CuAlO_(2) formation.Catalytic evaluation data demonstrated that CuAlO_(2) could catalyze MSR without pre-reduction,with the catalytic performance of CA-T catalysts being notably influenced by calcination temperature.Among the prepared catalysts,the CA-1100 catalyst exhibited the highest catalytic activity and stability.The findings of this study might be useful for the further study of the catalytic material for sustained release catalysis,including the synthesis of catalytic materials and the regulation of sustained release catalytic performance.展开更多
The new catalytic kinetic spectrophotometric method for Au（III） determination was developed and validated. It was based on the catalytic effect of gold on the oxidation of sudan red III by ammonium peroxodisulfate ...The new catalytic kinetic spectrophotometric method for Au（III） determination was developed and validated. It was based on the catalytic effect of gold on the oxidation of sudan red III by ammonium peroxodisulfate （（NH4）2S2O8） with nitrilo triacetic acid as an activator in microemulsion and H2SO4 medium. Under optimum conditions, there was the linearity of the calibration curve in the concentration range from 0 to 20 μg/L Au（Ⅲ） at 520 nm. The relative standard deviation was 3.0% with a correlation coefficient of 0.9986. The detection limit achieved was 9.75 × 10^-5 μg/mL. A new method using a column packed with sulfhydryl dextrose gel （SDG） as a solid-phase extractant has been developed for the preconcentration and separation of Au（Ⅲ） ions. The method has been applied to the determination of trace gold with satisfactory results.展开更多
Chitosan was prepared with stressing method by blending chitin and solid alkali in a single-screw extruder at given temperature and characterized by potentiometric titration, gel permeation chromatography (GPC), infra...Chitosan was prepared with stressing method by blending chitin and solid alkali in a single-screw extruder at given temperature and characterized by potentiometric titration, gel permeation chromatography (GPC), infrared spectrum (IR) and carbon-13 magnetic resonance sperctroscopy ( 13 C NMR) . Chitosan with a deacetylation degree (DD) of 76.1% was obtained at a mass ratio 0.2∶1∶1 for H_ 2 O/chitin/NaOH at 160 ℃ for 12 min. Compared to conventional solution method(usually 1∶10 for chitin/NaOH), the alkali assumption greatly decreased. Molecular weight of chitosan obtained by solid-phase method(S3,M_w1.54×10 5 ) was lower than that obtained by suspension method(Y2,M_w3.34×10 5 ). During deacetylation, molecular weight decreased with high reaction temperature and long reaction time but remained same at different initial ratios of NaOH/chitin. It might be concluded that degradation of chitosan was caused by breakout of the main chain of the oxidized chitosan catalyzed by alkali during the deactylation. IR and 13 C NMR showed that structures of chitosans prepared by solid-phase method were not changed.展开更多
AM1 and PM3 methods using the unrestricted Hartree-Fock (UHF) calculations have been applied to study the thermolysis of dicyanofuroxan. The results obtained show that the reaction proceeds to product through a two-st...AM1 and PM3 methods using the unrestricted Hartree-Fock (UHF) calculations have been applied to study the thermolysis of dicyanofuroxan. The results obtained show that the reaction proceeds to product through a two-step pathway where the second one is the rate-determining step.展开更多
UHF/AM1 method has been applied to study the thermolyses of o-aminobenzoyl, o-amino-p-methylbenzoyl, o-amino-p-formalbenzoyl azides. The results obtained show that these reactions proced through various competing rout...UHF/AM1 method has been applied to study the thermolyses of o-aminobenzoyl, o-amino-p-methylbenzoyl, o-amino-p-formalbenzoyl azides. The results obtained show that these reactions proced through various competing routes yielding to different products, and the activation energy of the rate-determining steps of routes (2)—(4) are lower than that of route(1).展开更多
采用水热法,以硫酸铝(Al2(SO4)3·18H2O)为原料、尿素为沉淀剂,在一定的醇水比例下(体积比2:1),制备出具有不同形貌的氧化铝前驱体,用SEM、XRD和TG-DSC分析对粉体的微观结构及热分解过程进行了研究。结果表明:相同条件下,水热处理...采用水热法,以硫酸铝(Al2(SO4)3·18H2O)为原料、尿素为沉淀剂,在一定的醇水比例下(体积比2:1),制备出具有不同形貌的氧化铝前驱体,用SEM、XRD和TG-DSC分析对粉体的微观结构及热分解过程进行了研究。结果表明:相同条件下,水热处理温度影响氧化铝前驱体的微观形貌及向α-Al2O3转变的温度,随水热处理温度的提高,其相结构由无定型态向结晶度高的薄水铝石相转变,而其煅烧产物向α-Al2O3转变的温度逐渐升高。利用Doyle-Ozawa法和Kissinger法计算经水热温度为100、140和160℃处理获得产物热分解过程的表观活化能,通过该两种方法得到的表面活化能平均值分别为150.68、155.46、171.09 k J/mol。用Kissinger法确定了反应级数、频率因子和不同水热处理温度下产物的热分解速率方程。展开更多
PM3 SCF calculations have been carried out to study the thermolyses of o-acetylcycolpentanone and o-acetylcyclohexanone. The results obtained show that these two com-pounds are thermally decomiposed into products thro...PM3 SCF calculations have been carried out to study the thermolyses of o-acetylcycolpentanone and o-acetylcyclohexanone. The results obtained show that these two com-pounds are thermally decomiposed into products through an unimolecular elimination involving six-center cyclic transition state, and these two thermolyses are caused by the migration of posi-tive charged β-H.展开更多
基金supported by the Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology(2023yjrc51)the National Natural Science Foundation of China(22172184)+2 种基金the Foundation of State Key Laboratory of Coal Conversion(J24-25-603)the Fundamental Research Project of ICC-CAS(SCJC-DT-2023-01)Weiqiao-UCAS Special Projects on Low-Carbon Technology Development(GYY-DTFZ-2022-015)。
文摘This study explores the controllable synthesis of CuAlO_(2) using copper hydroxide and pseudo-boehmite powders as raw materials via a simple solid-phase ball milling method,along with its catalytic performance investigation in methanol steam reforming(MSR).Various catalysts were prepared under different conditions,such as calcination temperature,calcination atmosphere,and heating rate.Characterization techniques including BET,XRD,XPS,SEM and H2-TPR were employed to analyze the samples.The results revealed significant effects of calcination temperature on the phase compositions,specific surface area,reduction performance,and surface properties of the CA-T catalysts.Based on the findings,a synthesis route of CuAlO_(2) via the solid-phase method was proposed,highlighting the importance of high calcination temperature,nitrogen atmosphere,and low heating rate for CuAlO_(2) formation.Catalytic evaluation data demonstrated that CuAlO_(2) could catalyze MSR without pre-reduction,with the catalytic performance of CA-T catalysts being notably influenced by calcination temperature.Among the prepared catalysts,the CA-1100 catalyst exhibited the highest catalytic activity and stability.The findings of this study might be useful for the further study of the catalytic material for sustained release catalysis,including the synthesis of catalytic materials and the regulation of sustained release catalytic performance.
文摘The new catalytic kinetic spectrophotometric method for Au（III） determination was developed and validated. It was based on the catalytic effect of gold on the oxidation of sudan red III by ammonium peroxodisulfate （（NH4）2S2O8） with nitrilo triacetic acid as an activator in microemulsion and H2SO4 medium. Under optimum conditions, there was the linearity of the calibration curve in the concentration range from 0 to 20 μg/L Au（Ⅲ） at 520 nm. The relative standard deviation was 3.0% with a correlation coefficient of 0.9986. The detection limit achieved was 9.75 × 10^-5 μg/mL. A new method using a column packed with sulfhydryl dextrose gel （SDG） as a solid-phase extractant has been developed for the preconcentration and separation of Au（Ⅲ） ions. The method has been applied to the determination of trace gold with satisfactory results.
文摘Chitosan was prepared with stressing method by blending chitin and solid alkali in a single-screw extruder at given temperature and characterized by potentiometric titration, gel permeation chromatography (GPC), infrared spectrum (IR) and carbon-13 magnetic resonance sperctroscopy ( 13 C NMR) . Chitosan with a deacetylation degree (DD) of 76.1% was obtained at a mass ratio 0.2∶1∶1 for H_ 2 O/chitin/NaOH at 160 ℃ for 12 min. Compared to conventional solution method(usually 1∶10 for chitin/NaOH), the alkali assumption greatly decreased. Molecular weight of chitosan obtained by solid-phase method(S3,M_w1.54×10 5 ) was lower than that obtained by suspension method(Y2,M_w3.34×10 5 ). During deacetylation, molecular weight decreased with high reaction temperature and long reaction time but remained same at different initial ratios of NaOH/chitin. It might be concluded that degradation of chitosan was caused by breakout of the main chain of the oxidized chitosan catalyzed by alkali during the deactylation. IR and 13 C NMR showed that structures of chitosans prepared by solid-phase method were not changed.
文摘AM1 and PM3 methods using the unrestricted Hartree-Fock (UHF) calculations have been applied to study the thermolysis of dicyanofuroxan. The results obtained show that the reaction proceeds to product through a two-step pathway where the second one is the rate-determining step.
文摘UHF/AM1 method has been applied to study the thermolyses of o-aminobenzoyl, o-amino-p-methylbenzoyl, o-amino-p-formalbenzoyl azides. The results obtained show that these reactions proced through various competing routes yielding to different products, and the activation energy of the rate-determining steps of routes (2)—(4) are lower than that of route(1).
文摘采用水热法,以硫酸铝(Al2(SO4)3·18H2O)为原料、尿素为沉淀剂,在一定的醇水比例下(体积比2:1),制备出具有不同形貌的氧化铝前驱体,用SEM、XRD和TG-DSC分析对粉体的微观结构及热分解过程进行了研究。结果表明:相同条件下,水热处理温度影响氧化铝前驱体的微观形貌及向α-Al2O3转变的温度,随水热处理温度的提高,其相结构由无定型态向结晶度高的薄水铝石相转变,而其煅烧产物向α-Al2O3转变的温度逐渐升高。利用Doyle-Ozawa法和Kissinger法计算经水热温度为100、140和160℃处理获得产物热分解过程的表观活化能,通过该两种方法得到的表面活化能平均值分别为150.68、155.46、171.09 k J/mol。用Kissinger法确定了反应级数、频率因子和不同水热处理温度下产物的热分解速率方程。
文摘PM3 SCF calculations have been carried out to study the thermolyses of o-acetylcycolpentanone and o-acetylcyclohexanone. The results obtained show that these two com-pounds are thermally decomiposed into products through an unimolecular elimination involving six-center cyclic transition state, and these two thermolyses are caused by the migration of posi-tive charged β-H.
