For the production of reactive polyurethane cross-linkinger and curing agents, 2, 4-diisocyanate toluene (TDI) terpolymer, which possesses the rigid structures of hexatomic ring and three reactive functional groups,...For the production of reactive polyurethane cross-linkinger and curing agents, 2, 4-diisocyanate toluene (TDI) terpolymer, which possesses the rigid structures of hexatomic ring and three reactive functional groups, was synthesized and characterized by the Fourier transform infrared (FFIR), the gel permeation chromatography (GPC) and the chemical analysis methods. The reaction conditions were studied and optimized. A tracking research on the polymerization process of TDI was taken by using the GPC. The formation processes of the terpolymer, oligomers and higher-polymers were also dealt with. Results show that the TDI terpolymer can be prepared in the presence of Cat-3 catalyst and at the reaction temperature of (60 ±2)℃. The reaction time is short, its outcomes have narrow molecular weights distribution, namely molecular weights from 530 to 550, Mw/Mn =1.10, and the mass fraction of NCO is (25. 0 ± 0. 5)%. With the reaction time prolonging, however, TDI can be further higher-polymedzed to form higher-polymers. Benzoyl chloride (0. 4%, mass fraction), as the stabilizing agent, can effectively inhibit the occurrence of higher-polymerization. The obtained TDI terpolymer can be stable for more than half a year.展开更多
As a decorative material, magnesium oxychloride cement was used as a photocatalyst supporter to purify the pollutants indoors. Due to excellent adsorption properties of activated carbon(AC), the photocatalytic compo...As a decorative material, magnesium oxychloride cement was used as a photocatalyst supporter to purify the pollutants indoors. Due to excellent adsorption properties of activated carbon(AC), the photocatalytic composties, TiO2/AC, were prepared and introduced into the porous magnesium oxychloride cement(PMOC) substrate to composite a sort of photocatalytic cementitious material(PCM). The optimal composite processes were assessed by gas chromatograph, using toluene as the target. By comparing the perspective of toluene purification and thorough decomposition, it can be found that the optimal mass ratio for TiO2/AC composites is 4/25, and the heat treatment to TiO2/AC sample at 350 ℃ can play the optimal synergetic role of adsorbents in photocatalytic process. The synergistic effect of TiO2, AC and magnesium oxychloride cement(MOC) was also evaluated by gas chromatograph. One-take molding process was adopted to introduce the TiO2/AC into PMOC substrate, and its optimal mass fraction was 4 wt%, while the appropriate density of substrate was 0.35 g/cm3. Toluene degradation showed that the prepared PCM can degrade pollutants efficiently. The appropriate treatment process of TiO2/AC, mass of TiO2/AC, substrate density, and stable pore structure should be coordinated to maximize the adsorption-photodegradation performance. The combination of photocatalytic materials, adsorbents, and building materials provided a new idea for the application of photocatalysis.展开更多
The experiment was carried out in a cylindrical dielectric barrier discharge(DBD)reactor assisted with a catalyst to decompose toluene under different humidity.In order to explore the synergistic effect on removing ...The experiment was carried out in a cylindrical dielectric barrier discharge(DBD)reactor assisted with a catalyst to decompose toluene under different humidity.In order to explore the synergistic effect on removing toluene in the catalysis-DBD reactor,this paper investigated the decomposition efficiency and the energy consumption in the catalysis-DBD and the non-catalyst DBD reactors under different humidity.The results showed that the catalysis-DBD reactor had a better performance than the non-catalysis one at the humidity ratio of 0.4%,and the removal efficiency of toluene could reach 88.6% in the catalysis-DBD reactor,while it was only 59.9% in the non-catalytic reactor.However,there was no significant difference in the removal efficiency of toluene between the two reactors when the humidities were 1.2% and 2.4%.Additionally,the degradation products were also analyzed in order to gain a better understanding of the mechanism of decomposing toluene in a catalysis-DBD reactor.展开更多
Synergistic effect of FeVO_4 withα-Fe_2O_3 was found in Fe-V-O catalyst,which was responsible for the high apparent formation rate(A.F.R.) of benzaldehyde in liquid phase oxidation of toluene by hydrogen peroxide.T...Synergistic effect of FeVO_4 withα-Fe_2O_3 was found in Fe-V-O catalyst,which was responsible for the high apparent formation rate(A.F.R.) of benzaldehyde in liquid phase oxidation of toluene by hydrogen peroxide.The synergistic effect might create VO_πspecies as active sites;moreover,it improved the reducibility and the reactivity of Fe-V-O catalyst.In order to gain the high A.F.R. of benzaldehyde,the catalyst should have the moderate reducibihty.展开更多
In order to efficiently remove volatile organic compounds(VOCs) from indoor air, onedimensional titanate nanotubes(Ti NTs) were hydrothermally treated to prepare TiO2 nanocrystals with different crystalline phases...In order to efficiently remove volatile organic compounds(VOCs) from indoor air, onedimensional titanate nanotubes(Ti NTs) were hydrothermally treated to prepare TiO2 nanocrystals with different crystalline phases, shapes and sizes. The influences of various acids such as CH3 COOH, HNO3, HCl, HF and H2SO4 used in the treatment were separately compared to optimize the performance of the TiO2 nanocrystals. Compared with the strong and corrosive inorganic acids, CH3COOH was not only safer and more environmentally friendly, but also more efficient in promoting the photocatalytic activity of the obtained TiO2. It was observed that the anatase TiO2 synthesized in 15 mol/L CH3COOH solution exhibited the highest photodegradation rate of gaseous toluene(94%), exceeding that of P25(44%) by a factor of more than two. The improved photocatalytic activity was attributed to the small crystallite size and surface modification by CH3COOH. The influence of relative humidity(20%–80%) on the performance of TiO2 nanocrystals was also studied. The anatase TiO2 synthesized in 15 mol/L CH3COOH solution was more tolerant to moisture than the other TiO2 nanocrystals and P25.展开更多
Highly sensitive and selective detection against specific target gases, especially at low-ppb (part per bil- lion) level, remain a great number of challenges in gas sensor applications. In this paper, we first prese...Highly sensitive and selective detection against specific target gases, especially at low-ppb (part per bil- lion) level, remain a great number of challenges in gas sensor applications. In this paper, we first present an ordered mesoporous NiFe204 for highly sensitive and selective detection against low-ppb toluene. A series of mesoporous NiFe204 materials were synthesized by templating from mesoporous silica KIT-6 and its framework thickness was reduced from 8.5 to 5 nm by varying the pore size of KIT-6 from 9.4 to 5.6 nm, accompanied with the increase of the specific surface area from 134 to 216 m^2 g^-1. The ordered mesoporous NiFe2O4 with both ultrathin framework of 5 nm and large specific surface area of up to 216 m^2 g^-1 exhibits a highest response (Rgas/Ralr-1 = 77.3) toward 1,000 ppb toluene at 230℃ and is nearly 7.3 and 76.7 times higher than those for the NiFe204 replica with thick framework and its bulk counter- part respectively, which also possesses a quite low limit of detection (〈2 ppb), and good selectivity.展开更多
CeO2 is an important porous material with a wide range of applications in the abatement of volatile organic compounds (VOCs). In this paper, we prepared a series of novel three-dimensional (3D) micro/nanostructure...CeO2 is an important porous material with a wide range of applications in the abatement of volatile organic compounds (VOCs). In this paper, we prepared a series of novel three-dimensional (3D) micro/nanostructured CeO2 materials via a solvothermal method. Organic acid-assisted synthesis and inorganic acid post-treatment were used to adjust the Ce02 microstructures. The size of the 3D micro/nanostructures could be controlled in the range from 180nm to 1.5 μm and the surface morphology changed from rough to smooth with the use of different organic acids. The CeO2 synthesized with acetic acid featured a hierarchical porosity and showed good performance for toluene catalytic combustion: a T50 of 187 ℃ and a T90 of 195 ℃. Moreover, the crystallite size, textural properties, and surface chemical states could be tuned by inorganic acid modification. After treatment with HNO3, the modified CeO2 materials exhibited improved catalytic activity, with a T50 of-175 ℃ and a T90 of -187 ℃. We concluded that the toluene combustion activity is related to the porosity and the amount of surface active oxygen of the CeO2. Both these features can be tuned by the co-work of organic and inorganic acids.展开更多
文摘For the production of reactive polyurethane cross-linkinger and curing agents, 2, 4-diisocyanate toluene (TDI) terpolymer, which possesses the rigid structures of hexatomic ring and three reactive functional groups, was synthesized and characterized by the Fourier transform infrared (FFIR), the gel permeation chromatography (GPC) and the chemical analysis methods. The reaction conditions were studied and optimized. A tracking research on the polymerization process of TDI was taken by using the GPC. The formation processes of the terpolymer, oligomers and higher-polymers were also dealt with. Results show that the TDI terpolymer can be prepared in the presence of Cat-3 catalyst and at the reaction temperature of (60 ±2)℃. The reaction time is short, its outcomes have narrow molecular weights distribution, namely molecular weights from 530 to 550, Mw/Mn =1.10, and the mass fraction of NCO is (25. 0 ± 0. 5)%. With the reaction time prolonging, however, TDI can be further higher-polymedzed to form higher-polymers. Benzoyl chloride (0. 4%, mass fraction), as the stabilizing agent, can effectively inhibit the occurrence of higher-polymerization. The obtained TDI terpolymer can be stable for more than half a year.
基金Funded by the National Natural Science Foundation of China(No.51478370)
文摘As a decorative material, magnesium oxychloride cement was used as a photocatalyst supporter to purify the pollutants indoors. Due to excellent adsorption properties of activated carbon(AC), the photocatalytic composties, TiO2/AC, were prepared and introduced into the porous magnesium oxychloride cement(PMOC) substrate to composite a sort of photocatalytic cementitious material(PCM). The optimal composite processes were assessed by gas chromatograph, using toluene as the target. By comparing the perspective of toluene purification and thorough decomposition, it can be found that the optimal mass ratio for TiO2/AC composites is 4/25, and the heat treatment to TiO2/AC sample at 350 ℃ can play the optimal synergetic role of adsorbents in photocatalytic process. The synergistic effect of TiO2, AC and magnesium oxychloride cement(MOC) was also evaluated by gas chromatograph. One-take molding process was adopted to introduce the TiO2/AC into PMOC substrate, and its optimal mass fraction was 4 wt%, while the appropriate density of substrate was 0.35 g/cm3. Toluene degradation showed that the prepared PCM can degrade pollutants efficiently. The appropriate treatment process of TiO2/AC, mass of TiO2/AC, substrate density, and stable pore structure should be coordinated to maximize the adsorption-photodegradation performance. The combination of photocatalytic materials, adsorbents, and building materials provided a new idea for the application of photocatalysis.
基金supported by the Key Project which is sponsored by the Science and Technology Commission of Shanghai Municipality(No.13231201903)the Key Programs for Science and Technology Development sponsored by the Science and Technology Commission of Shanghai Municipality(Nos.13231201901 and 14DZ1208401)the Key Project sponsored by the State-owned Assets Supervision and Administration Commission of Shanghai,China(No.2013019)
文摘The experiment was carried out in a cylindrical dielectric barrier discharge(DBD)reactor assisted with a catalyst to decompose toluene under different humidity.In order to explore the synergistic effect on removing toluene in the catalysis-DBD reactor,this paper investigated the decomposition efficiency and the energy consumption in the catalysis-DBD and the non-catalyst DBD reactors under different humidity.The results showed that the catalysis-DBD reactor had a better performance than the non-catalysis one at the humidity ratio of 0.4%,and the removal efficiency of toluene could reach 88.6% in the catalysis-DBD reactor,while it was only 59.9% in the non-catalytic reactor.However,there was no significant difference in the removal efficiency of toluene between the two reactors when the humidities were 1.2% and 2.4%.Additionally,the degradation products were also analyzed in order to gain a better understanding of the mechanism of decomposing toluene in a catalysis-DBD reactor.
基金supported by Ministry of Education(NoNCET-10-878,20096101120018,2009-37th of SRFROCS)Shaanxi Province(No2009ZDKG-70,09JK793)+1 种基金Northwest University(NoPR09005,10YSY08)State Key Lab for SSPC(2009)
文摘Synergistic effect of FeVO_4 withα-Fe_2O_3 was found in Fe-V-O catalyst,which was responsible for the high apparent formation rate(A.F.R.) of benzaldehyde in liquid phase oxidation of toluene by hydrogen peroxide.The synergistic effect might create VO_πspecies as active sites;moreover,it improved the reducibility and the reactivity of Fe-V-O catalyst.In order to gain the high A.F.R. of benzaldehyde,the catalyst should have the moderate reducibihty.
基金supported by grants from National High Technology Research and Development Program of China (863) (No. 2012AA062702 and 2010AA064902)the Key Innovation Team for Science and Technology of Zhejiang Province (No. 2009R50047)
文摘In order to efficiently remove volatile organic compounds(VOCs) from indoor air, onedimensional titanate nanotubes(Ti NTs) were hydrothermally treated to prepare TiO2 nanocrystals with different crystalline phases, shapes and sizes. The influences of various acids such as CH3 COOH, HNO3, HCl, HF and H2SO4 used in the treatment were separately compared to optimize the performance of the TiO2 nanocrystals. Compared with the strong and corrosive inorganic acids, CH3COOH was not only safer and more environmentally friendly, but also more efficient in promoting the photocatalytic activity of the obtained TiO2. It was observed that the anatase TiO2 synthesized in 15 mol/L CH3COOH solution exhibited the highest photodegradation rate of gaseous toluene(94%), exceeding that of P25(44%) by a factor of more than two. The improved photocatalytic activity was attributed to the small crystallite size and surface modification by CH3COOH. The influence of relative humidity(20%–80%) on the performance of TiO2 nanocrystals was also studied. The anatase TiO2 synthesized in 15 mol/L CH3COOH solution was more tolerant to moisture than the other TiO2 nanocrystals and P25.
基金supported by the National First-Rate Discipline Construction Project of Ningxia(NXYLXK2017A04,2017CET02KY03,and 2017CET04KY05)the National Natural Science Foundation of China(51362024,21006116,and 51672138)+2 种基金the Foundation of State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering(2016–19)National Science Fund for Distinguished Young Scholars(21325105)the West Light Foundation of the Chinese Academy of Science
文摘Highly sensitive and selective detection against specific target gases, especially at low-ppb (part per bil- lion) level, remain a great number of challenges in gas sensor applications. In this paper, we first present an ordered mesoporous NiFe204 for highly sensitive and selective detection against low-ppb toluene. A series of mesoporous NiFe204 materials were synthesized by templating from mesoporous silica KIT-6 and its framework thickness was reduced from 8.5 to 5 nm by varying the pore size of KIT-6 from 9.4 to 5.6 nm, accompanied with the increase of the specific surface area from 134 to 216 m^2 g^-1. The ordered mesoporous NiFe2O4 with both ultrathin framework of 5 nm and large specific surface area of up to 216 m^2 g^-1 exhibits a highest response (Rgas/Ralr-1 = 77.3) toward 1,000 ppb toluene at 230℃ and is nearly 7.3 and 76.7 times higher than those for the NiFe204 replica with thick framework and its bulk counter- part respectively, which also possesses a quite low limit of detection (〈2 ppb), and good selectivity.
基金This work was financially supported by the Natural Science Foundation of China (21576054), the Scientific Project of Guangdong Province (2014A010106030, 2016A010104017,2016B020241003), and the Foundation of Higher Education of Guangdong Province (201 SICFSCX027) of China.
文摘CeO2 is an important porous material with a wide range of applications in the abatement of volatile organic compounds (VOCs). In this paper, we prepared a series of novel three-dimensional (3D) micro/nanostructured CeO2 materials via a solvothermal method. Organic acid-assisted synthesis and inorganic acid post-treatment were used to adjust the Ce02 microstructures. The size of the 3D micro/nanostructures could be controlled in the range from 180nm to 1.5 μm and the surface morphology changed from rough to smooth with the use of different organic acids. The CeO2 synthesized with acetic acid featured a hierarchical porosity and showed good performance for toluene catalytic combustion: a T50 of 187 ℃ and a T90 of 195 ℃. Moreover, the crystallite size, textural properties, and surface chemical states could be tuned by inorganic acid modification. After treatment with HNO3, the modified CeO2 materials exhibited improved catalytic activity, with a T50 of-175 ℃ and a T90 of -187 ℃. We concluded that the toluene combustion activity is related to the porosity and the amount of surface active oxygen of the CeO2. Both these features can be tuned by the co-work of organic and inorganic acids.