Anthraquinone hydrogenation to produce H_(2)O_(2) is an economically interesting reaction with great industrial importance.Here,we report a series of Pd/xAl catalysts with different AlCl_(3) contents by a conventional...Anthraquinone hydrogenation to produce H_(2)O_(2) is an economically interesting reaction with great industrial importance.Here,we report a series of Pd/xAl catalysts with different AlCl_(3) contents by a conventional stepwise impregnation method.The optimal Pd/1.0Al catalyst exhibits a higher performance toward anthraquinone hydrogenation with 8.3 g·L^(-1)hydrogenation efficiency,99.5%selectivity and good stability,obviously superior to that of Pd/Al_(2)O_(3) catalyst(5.2 g·L^(-1)and 97.2%).Detailed characterization demonstrates that AlCl_(3) can be grafted on the γ-Al_(2)O_(3) support to obtain a modified support with abundant surface weak acid and Lewis acid,which can adsorb and activate anthraquinone.Meanwhile,its steric hindrance could isolate and disperse active metals to form more active sites.The synergies between metal sites and acid sites promotes the anthraquinone hydrogenation.Furthermore,the good stability after grafting AlCl_(3) could attribute to the enhanced metal-support interaction inhibiting metal particles agglomeration and leaching.展开更多
The Ni-Nb_(2)O_(5)nanocatalysts have been prepared by the solgel method,and the catalytic hydrodeoxygenation(HDO)performance of anisole as model compound is studied.The results show that Nb exists as amorphous Nb_(2)O...The Ni-Nb_(2)O_(5)nanocatalysts have been prepared by the solgel method,and the catalytic hydrodeoxygenation(HDO)performance of anisole as model compound is studied.The results show that Nb exists as amorphous Nb_(2)O_(5)species,which can promote Ni dispersion.The addition of Nb_(2)O_(5)increases the acidity of the catalyst.However,when the content of niobium is high,there is an inactive Nb-Ni-O mixed phase.The size and morphology of Ni grains in catalysts are different due to the difference of Nb/Ni molar ratio.The Ni_(0.9)Nb_(0.1)sample has the largest surface area of 170.8 m^(2)·g^(-1)among the catalysts prepared in different Nb/Ni molar ratios,which is mainly composed of spherical nanoparticles and crack pores.The HDO of anisole follows the reaction route of the hydrogenation HYD route.The Ni_(0.9)Nb_(0.1)catalyst displayed a higher HDO performance for anisole than Ni catalyst.The selectivity to cyclohexane over the Ni_(0.9)Nb_(0.1)sample is about 10 times that of Ni catalyst at 220℃and 3 MPa H_(2).The selectivity of cyclohexane is increased with the increase of reaction temperature.The anisole is almost completely transformed into cyclohexane at 240℃,3 MPa H_(2)and 4 h.展开更多
Perovskite oxides(POs)are emerging as a class of highly efficient catalysts for reducing oxygen to H_(2)O.Although a rich variety of POs-based catalysts have been developed by tuning the complex composition,a highly e...Perovskite oxides(POs)are emerging as a class of highly efficient catalysts for reducing oxygen to H_(2)O.Although a rich variety of POs-based catalysts have been developed by tuning the complex composition,a highly efficient PO catalyst that is able to alter the reaction pathway from a 4e−process to a 2e−process for H_(2)O_(2)production has rarely been achieved.We modified the structure and composition of a Ca-and Nb-based PO material by realizing a uniform two-dimensional(2D)morphology and varied Ta doping,resulting in the 2D Ca_(2)Nb_(3−x)Ta_(x)O_(10)−(x=0,0.5,1,and 1.5)monolayer catalysts.The obtained catalysts exhibit a dominant 2e−pathway and show exceptional H_(2)O_(2)production efficiency.The typical Ca_(2)Nb_(2.5)Ta_(0.5)O_(10)−nanoflakes showed an onset potential of 0.735 V vs.reversible hydrogen electrode(RHE),a remarkably high selectivity over 95%across a wide range of 0.3-0.7 V,an impressively high Faradaic efficiency of 94%,and a notable H_(2)O_(2)productivity of 1571 mmol·gcat^(−1)·h^(−1).These findings highlight the great potential of 2D perovskite oxide nanoflakes as advanced electrocatalysts for 2e−oxygen reduction reaction.展开更多
以氢氧化铝干胶和六水合硝酸镍为原料,采用湿混捏法制备不同NiO含量的NiO/Al_(2)O_(3)催化剂,利用N_(2)吸附-脱附、XRD、NH_(3)-TPD、TPR和Py-IR等方法对所制备催化剂进行表征,以溴指数为4300 mg(100 g Br)的重整生成油为评价原料对所...以氢氧化铝干胶和六水合硝酸镍为原料,采用湿混捏法制备不同NiO含量的NiO/Al_(2)O_(3)催化剂,利用N_(2)吸附-脱附、XRD、NH_(3)-TPD、TPR和Py-IR等方法对所制备催化剂进行表征,以溴指数为4300 mg(100 g Br)的重整生成油为评价原料对所制备催化剂进行选择加氢脱烯烃活性评价。实验结果表明,在NiO含量30%~50%(w)的范围内,随着NiO含量的增加,NiO/Al_(2)O_(3)催化剂的比表面积和孔体积逐渐减小,平均孔径增大,总酸量增加,NiO的粒径逐渐增大;NiO/Al_(2)O_(3)催化剂只有L酸,没有B酸,NiO含量为30%(w)时,NiO晶粒较小,分散相对均匀,芳烃加氢率最高,烯烃选择加氢活性较低;NiO含量大于40%(w)时,NiO晶粒逐渐变大,出现镍铝尖晶石晶相,芳烃加氢活性降低,烯烃加氢选择性增加。展开更多
基金National Natural Science Foundation of China(12175254,U1832119)National Key R&D Program of China(2021YFE0104800)+2 种基金International Partnership Program of Chinese Academy of Sciences(121631KYSB20200039)International Cooperation Project of Shanghai Science and Technology Commission(20520750200)National Centre for Research and Development(WPC2/1/SCAPOL/2021)。
基金the National Natural Science Foundation of China(21776215 and 21621004).
文摘Anthraquinone hydrogenation to produce H_(2)O_(2) is an economically interesting reaction with great industrial importance.Here,we report a series of Pd/xAl catalysts with different AlCl_(3) contents by a conventional stepwise impregnation method.The optimal Pd/1.0Al catalyst exhibits a higher performance toward anthraquinone hydrogenation with 8.3 g·L^(-1)hydrogenation efficiency,99.5%selectivity and good stability,obviously superior to that of Pd/Al_(2)O_(3) catalyst(5.2 g·L^(-1)and 97.2%).Detailed characterization demonstrates that AlCl_(3) can be grafted on the γ-Al_(2)O_(3) support to obtain a modified support with abundant surface weak acid and Lewis acid,which can adsorb and activate anthraquinone.Meanwhile,its steric hindrance could isolate and disperse active metals to form more active sites.The synergies between metal sites and acid sites promotes the anthraquinone hydrogenation.Furthermore,the good stability after grafting AlCl_(3) could attribute to the enhanced metal-support interaction inhibiting metal particles agglomeration and leaching.
基金Major Science and Technology Project of Yunnan Province(202102AE090042)National Natural Science Foundation of China(21766016)+1 种基金the Science and Technology Talent and Platform Program of Yunnan Provincial Science and Technology Department(202005AF150037)the financial support of Taif University Researchers Supporting Project(TURSP-2020/27),Taif University,Taif,Saudi Arabia。
文摘The Ni-Nb_(2)O_(5)nanocatalysts have been prepared by the solgel method,and the catalytic hydrodeoxygenation(HDO)performance of anisole as model compound is studied.The results show that Nb exists as amorphous Nb_(2)O_(5)species,which can promote Ni dispersion.The addition of Nb_(2)O_(5)increases the acidity of the catalyst.However,when the content of niobium is high,there is an inactive Nb-Ni-O mixed phase.The size and morphology of Ni grains in catalysts are different due to the difference of Nb/Ni molar ratio.The Ni_(0.9)Nb_(0.1)sample has the largest surface area of 170.8 m^(2)·g^(-1)among the catalysts prepared in different Nb/Ni molar ratios,which is mainly composed of spherical nanoparticles and crack pores.The HDO of anisole follows the reaction route of the hydrogenation HYD route.The Ni_(0.9)Nb_(0.1)catalyst displayed a higher HDO performance for anisole than Ni catalyst.The selectivity to cyclohexane over the Ni_(0.9)Nb_(0.1)sample is about 10 times that of Ni catalyst at 220℃and 3 MPa H_(2).The selectivity of cyclohexane is increased with the increase of reaction temperature.The anisole is almost completely transformed into cyclohexane at 240℃,3 MPa H_(2)and 4 h.
基金the National Key Research and development Program of China(Nos.2022YFF0712200 and 2021YFA1202802)the Young Elite Scientists Sponsorship Program by BAST(No.BYESS2023410)+1 种基金the visiting scholars fund support from State Key Lab of Silicon Materials,Zhejiang University(No.SKL2022-04)the CAS Pioneer Hundred Talents Program.
文摘Perovskite oxides(POs)are emerging as a class of highly efficient catalysts for reducing oxygen to H_(2)O.Although a rich variety of POs-based catalysts have been developed by tuning the complex composition,a highly efficient PO catalyst that is able to alter the reaction pathway from a 4e−process to a 2e−process for H_(2)O_(2)production has rarely been achieved.We modified the structure and composition of a Ca-and Nb-based PO material by realizing a uniform two-dimensional(2D)morphology and varied Ta doping,resulting in the 2D Ca_(2)Nb_(3−x)Ta_(x)O_(10)−(x=0,0.5,1,and 1.5)monolayer catalysts.The obtained catalysts exhibit a dominant 2e−pathway and show exceptional H_(2)O_(2)production efficiency.The typical Ca_(2)Nb_(2.5)Ta_(0.5)O_(10)−nanoflakes showed an onset potential of 0.735 V vs.reversible hydrogen electrode(RHE),a remarkably high selectivity over 95%across a wide range of 0.3-0.7 V,an impressively high Faradaic efficiency of 94%,and a notable H_(2)O_(2)productivity of 1571 mmol·gcat^(−1)·h^(−1).These findings highlight the great potential of 2D perovskite oxide nanoflakes as advanced electrocatalysts for 2e−oxygen reduction reaction.
文摘以氢氧化铝干胶和六水合硝酸镍为原料,采用湿混捏法制备不同NiO含量的NiO/Al_(2)O_(3)催化剂,利用N_(2)吸附-脱附、XRD、NH_(3)-TPD、TPR和Py-IR等方法对所制备催化剂进行表征,以溴指数为4300 mg(100 g Br)的重整生成油为评价原料对所制备催化剂进行选择加氢脱烯烃活性评价。实验结果表明,在NiO含量30%~50%(w)的范围内,随着NiO含量的增加,NiO/Al_(2)O_(3)催化剂的比表面积和孔体积逐渐减小,平均孔径增大,总酸量增加,NiO的粒径逐渐增大;NiO/Al_(2)O_(3)催化剂只有L酸,没有B酸,NiO含量为30%(w)时,NiO晶粒较小,分散相对均匀,芳烃加氢率最高,烯烃选择加氢活性较低;NiO含量大于40%(w)时,NiO晶粒逐渐变大,出现镍铝尖晶石晶相,芳烃加氢活性降低,烯烃加氢选择性增加。
