Commercial production of vinyl chloride from acetylene relies on the use of HgCla as the catalyst, which has caused severe environmental problem and threats to human health because of its toxicity. Therefore, it is vi...Commercial production of vinyl chloride from acetylene relies on the use of HgCla as the catalyst, which has caused severe environmental problem and threats to human health because of its toxicity. Therefore, it is vital to explore alternative catalysts without mercury. We report here that N-doped carbon can catalyze directly transformation of acetylene to vinyl chloride. Particularly, N-doped high surface area mesoporous carbon exhibits a rather high activity with the acetylene conversion reaching 77% and vinyl chloride selectivity above 98% at a space velocity of 1.0 mL.min-l.g-1 and 200 ~C. It delivers a stable performa℃nce within a test period of 100h and no obvious deactivation is observed, demonstrating potentials to substitute the notoriously toxic mercuric chloride catalyst.展开更多
Commercialization of acetylene hydrochlorination using AuCl3 catalysts has been impeded by its poor stability. We have been studying that nitrogen-modified Au/NAC catalyst delivered a stable performance which can impr...Commercialization of acetylene hydrochlorination using AuCl3 catalysts has been impeded by its poor stability. We have been studying that nitrogen-modified Au/NAC catalyst delivered a stable performance which can improve acetylene hydrochlorination activity and has resistance to catalytic deactivation. Here we show that nitrogen and sulfur co-doped activated carbon supported AuCl3 catalyst worked as efficient catalysts for the hydrochlorination of acetylene to vinyl chloride. Au/NSAC catalyst demonstrated high activity comparative to Au/AC catalyst. Furthermore, it also delivered stable performance within the selectivity of acetylene, reaching more than 99.5%, and there was only a 3.3% C2H2 conversion loss after running for 12 h under the reaction conditions of a temperature of 180 C and a C2H2 hourly space velocity of 1480 h 1. The presence of the sulfur atoms may serve to immobilize/ anchor the Au and also help prevent reduction and sintering of the Au and hence improve the catalytic activity and stability. The excellent catalytic performance of the Au/NSAC catalyst demonstrated its potential as an alternative to mercury chloride catalysts for acetylene hydrochlorination.展开更多
Catalyst supports have very important effects on catalyst performance.A novel expanded multilayered vermiculite（EML-VMT） is successfully used as the catalyst support for the acetylene hydrochlorination.By mixing car...Catalyst supports have very important effects on catalyst performance.A novel expanded multilayered vermiculite（EML-VMT） is successfully used as the catalyst support for the acetylene hydrochlorination.By mixing carbon on the surface of EML-VMT[i.e.,EML-VMT-C）,the HgCl2/EML-VMT-C achieved a high acetylene conversion of 97.3%,a vinyl chloride selectivity of 100%and a turn over frequency（TOF） value of 8.83 × 10^-3s^-1 at a temperature of 140 C,an acetylene gas hourly space velocity（GHSV） of 108 h^-1,and a feed volume ratio V（HC1）/V（C2H2） of 1.15.Moreover,the HgCl2/EML-VMT-C shows good stability.The EML-VMT also shows potential in the preparation of other EML-VMT-supported catalysts.展开更多
AuCl3 loaded structured catalysts were prepared on SiC foam supported with pre-coated activated carbon layers. The catalytic properties of the structured catalysts towards hydrochlorination of acetylene were tested in...AuCl3 loaded structured catalysts were prepared on SiC foam supported with pre-coated activated carbon layers. The catalytic properties of the structured catalysts towards hydrochlorination of acetylene were tested in a fixed- bed reactor with the AuCl3 loaded on activated carbon pellets as a reference. For isopyknic catalysts, the structured catalyst with only one fifth of the Au amount as that was used on the reference catalyst exhibited even a little higher acetylene conversion and much better stability than the latter no matter what the gas hourly space velocities of acetylene were used. The results indicated that the more homogeneous distribution of AuCl3 particles and better heat transfer along the fixed-bed reactor originated from the low pressure drop and high thermal conductivity of the SiC foam supported structured catalysts might be able to account for their improved efficiency and stability. It is befieved that these novel structured C/Au catalysts can be potentially applied in VCM industrialization in view of their greatly reduced cost and much prolonged life.展开更多
Herein,we report an excellent,supported Ru(III)‐ChCl/AC catalyst with lower Ru content,where the ionic complex ChRuCl4 serves as the active component for acetylene hydrochlorination.The prepared heterogeneous Ru‐10%...Herein,we report an excellent,supported Ru(III)‐ChCl/AC catalyst with lower Ru content,where the ionic complex ChRuCl4 serves as the active component for acetylene hydrochlorination.The prepared heterogeneous Ru‐10%ChCl/AC catalyst shows excellent activity and long‐term stability.In this system,ChCl provides an environment for the ChRuCl4 to be stabilized as Ru(III),thus suppressing the reduction of the active species and the aggregation of ruthenium species during the reaction.The interaction between reactants and catalyst species was investigated by catalyst characterizations in combination with DFT calculations to disclose the effect of the ChRuCl4 complex and ChCl on the catalytic performance.This inexpensive,efficient,and long‐term catalyst is a competitive candidate for application in the hydrochlorination industry.展开更多
Activated carbon-supported mercuric chloride（HgCl2） is used as an industrial catalyst for acetylene hydrochlorination. However, the characteristic of easy sublimation of HgCl2 leads to the deactivation o the catalys...Activated carbon-supported mercuric chloride（HgCl2） is used as an industrial catalyst for acetylene hydrochlorination. However, the characteristic of easy sublimation of HgCl2 leads to the deactivation o the catalyst. Here, we showed that the thermal stability of the Hg/AC catalyst can be evidently improved when Cs Cl is added into the Hg/AC catalyst. Compared with the pure Hg/AC catalyst, the sublimation rate of HgCl2 from the Hg–Cs/AC catalyst decreased significantly and the Hg–Cs/AC catalyst showed bette catalytic activity and stability in the reaction. This promoting effect is related to the existence of cesium mercuric chlorides（CsxHgyCl（x＋2y）） highlighted by XRD, HR-TEM and EDX analyses. Thus, reacting HgCl2 with alkali chlorides to form alkali-mercuric chlorides may be a key to design highly efficient and thermally stable mercuric chloride catalyst for hydrochlorination reactions.展开更多
Nitrogen‐doped ordered mesoporous carbon （N‐OMC） catalysts were directly synthesized using SBA‐15 as a hard template and sucrose as a carbon source. Urea, which was used as the nitrogen source, was carbonized wit...Nitrogen‐doped ordered mesoporous carbon （N‐OMC） catalysts were directly synthesized using SBA‐15 as a hard template and sucrose as a carbon source. Urea, which was used as the nitrogen source, was carbonized with sucrose. A 3.6 wt% nitrogen doping of the carbon framework was achieved, with more than 70%of the nitrogen incorporated as quaternary nitrogen species. Only 0.2 wt% nitrogen doping, with only 32.7% quaternary nitrogen incorporation was obtained in an N‐OMC catalyst （N‐OMC‐T） prepared using a two‐step post‐synthesis method. The acetylene hy‐drochlorination activities of N‐OMC catalysts prepared via the one‐step method were higher than that of the N‐OMC‐T catalyst because of the higher nitrogen loadings.展开更多
In this review we discuss the history of research into the use of gold for the acetylene hydrochlorin‐ation reaction, and describe the recent developments which have led to its commercialisation. We discuss the use o...In this review we discuss the history of research into the use of gold for the acetylene hydrochlorin‐ation reaction, and describe the recent developments which have led to its commercialisation. We discuss the use of different precursors and the addition to gold of a secondary metal as methods which attempt to improve these catalysts, and consider the nature of the active gold species. The vast majority of poly vinyl chloride （PVC） produced globally still uses a mercuric chloride as a cata‐lyst, despite the environmental problems associated with it. Due to the agreement by the Chinese government to remove mercury usage in the PVC industry over the course of the next few years there is an obvious need to find a replacement catalyst;the potential use of gold for this process has been well known for several decades and to date gold seems to be the best candidate for this, pri‐marily due to its superior selectivity when compared to other metals.展开更多
基金supported by the Natural Science Foundation of China(No.11079005 and 21033009)the Ministry of Science and Technology of China(2011CBA00503 and 2012CB720302)
文摘Commercial production of vinyl chloride from acetylene relies on the use of HgCla as the catalyst, which has caused severe environmental problem and threats to human health because of its toxicity. Therefore, it is vital to explore alternative catalysts without mercury. We report here that N-doped carbon can catalyze directly transformation of acetylene to vinyl chloride. Particularly, N-doped high surface area mesoporous carbon exhibits a rather high activity with the acetylene conversion reaching 77% and vinyl chloride selectivity above 98% at a space velocity of 1.0 mL.min-l.g-1 and 200 ~C. It delivers a stable performa℃nce within a test period of 100h and no obvious deactivation is observed, demonstrating potentials to substitute the notoriously toxic mercuric chloride catalyst.
文摘Commercialization of acetylene hydrochlorination using AuCl3 catalysts has been impeded by its poor stability. We have been studying that nitrogen-modified Au/NAC catalyst delivered a stable performance which can improve acetylene hydrochlorination activity and has resistance to catalytic deactivation. Here we show that nitrogen and sulfur co-doped activated carbon supported AuCl3 catalyst worked as efficient catalysts for the hydrochlorination of acetylene to vinyl chloride. Au/NSAC catalyst demonstrated high activity comparative to Au/AC catalyst. Furthermore, it also delivered stable performance within the selectivity of acetylene, reaching more than 99.5%, and there was only a 3.3% C2H2 conversion loss after running for 12 h under the reaction conditions of a temperature of 180 C and a C2H2 hourly space velocity of 1480 h 1. The presence of the sulfur atoms may serve to immobilize/ anchor the Au and also help prevent reduction and sintering of the Au and hence improve the catalytic activity and stability. The excellent catalytic performance of the Au/NSAC catalyst demonstrated its potential as an alternative to mercury chloride catalysts for acetylene hydrochlorination.
基金financially supported by National Natural Science Foundation of China(Nos.21163015,21366027)the Doctor Foundation of Bingtuan(No.2014BB004)+2 种基金the National Basic Research Program of China(973Program,No. 2012CB720300)the Program for Changjiang Scholars,Innovative Research Team in University(No.IRT1161)the Program of Science and Technology Innovation Team in Bingtuan(No.2011CC001)
文摘Catalyst supports have very important effects on catalyst performance.A novel expanded multilayered vermiculite（EML-VMT） is successfully used as the catalyst support for the acetylene hydrochlorination.By mixing carbon on the surface of EML-VMT[i.e.,EML-VMT-C）,the HgCl2/EML-VMT-C achieved a high acetylene conversion of 97.3%,a vinyl chloride selectivity of 100%and a turn over frequency（TOF） value of 8.83 × 10^-3s^-1 at a temperature of 140 C,an acetylene gas hourly space velocity（GHSV） of 108 h^-1,and a feed volume ratio V（HC1）/V（C2H2） of 1.15.Moreover,the HgCl2/EML-VMT-C shows good stability.The EML-VMT also shows potential in the preparation of other EML-VMT-supported catalysts.
基金supported by the National Key Technology R&D Program of China with Grant No.2011BAE03B07
文摘AuCl3 loaded structured catalysts were prepared on SiC foam supported with pre-coated activated carbon layers. The catalytic properties of the structured catalysts towards hydrochlorination of acetylene were tested in a fixed- bed reactor with the AuCl3 loaded on activated carbon pellets as a reference. For isopyknic catalysts, the structured catalyst with only one fifth of the Au amount as that was used on the reference catalyst exhibited even a little higher acetylene conversion and much better stability than the latter no matter what the gas hourly space velocities of acetylene were used. The results indicated that the more homogeneous distribution of AuCl3 particles and better heat transfer along the fixed-bed reactor originated from the low pressure drop and high thermal conductivity of the SiC foam supported structured catalysts might be able to account for their improved efficiency and stability. It is befieved that these novel structured C/Au catalysts can be potentially applied in VCM industrialization in view of their greatly reduced cost and much prolonged life.
文摘Herein,we report an excellent,supported Ru(III)‐ChCl/AC catalyst with lower Ru content,where the ionic complex ChRuCl4 serves as the active component for acetylene hydrochlorination.The prepared heterogeneous Ru‐10%ChCl/AC catalyst shows excellent activity and long‐term stability.In this system,ChCl provides an environment for the ChRuCl4 to be stabilized as Ru(III),thus suppressing the reduction of the active species and the aggregation of ruthenium species during the reaction.The interaction between reactants and catalyst species was investigated by catalyst characterizations in combination with DFT calculations to disclose the effect of the ChRuCl4 complex and ChCl on the catalytic performance.This inexpensive,efficient,and long‐term catalyst is a competitive candidate for application in the hydrochlorination industry.
文摘Activated carbon-supported mercuric chloride（HgCl2） is used as an industrial catalyst for acetylene hydrochlorination. However, the characteristic of easy sublimation of HgCl2 leads to the deactivation o the catalyst. Here, we showed that the thermal stability of the Hg/AC catalyst can be evidently improved when Cs Cl is added into the Hg/AC catalyst. Compared with the pure Hg/AC catalyst, the sublimation rate of HgCl2 from the Hg–Cs/AC catalyst decreased significantly and the Hg–Cs/AC catalyst showed bette catalytic activity and stability in the reaction. This promoting effect is related to the existence of cesium mercuric chlorides（CsxHgyCl（x＋2y）） highlighted by XRD, HR-TEM and EDX analyses. Thus, reacting HgCl2 with alkali chlorides to form alkali-mercuric chlorides may be a key to design highly efficient and thermally stable mercuric chloride catalyst for hydrochlorination reactions.
基金supported by the National Natural Science Foundation of China (20803064)the Natural Science Foundation of Zhejiang Province (Y4090348)~~
文摘Nitrogen‐doped ordered mesoporous carbon （N‐OMC） catalysts were directly synthesized using SBA‐15 as a hard template and sucrose as a carbon source. Urea, which was used as the nitrogen source, was carbonized with sucrose. A 3.6 wt% nitrogen doping of the carbon framework was achieved, with more than 70%of the nitrogen incorporated as quaternary nitrogen species. Only 0.2 wt% nitrogen doping, with only 32.7% quaternary nitrogen incorporation was obtained in an N‐OMC catalyst （N‐OMC‐T） prepared using a two‐step post‐synthesis method. The acetylene hy‐drochlorination activities of N‐OMC catalysts prepared via the one‐step method were higher than that of the N‐OMC‐T catalyst because of the higher nitrogen loadings.
文摘In this review we discuss the history of research into the use of gold for the acetylene hydrochlorin‐ation reaction, and describe the recent developments which have led to its commercialisation. We discuss the use of different precursors and the addition to gold of a secondary metal as methods which attempt to improve these catalysts, and consider the nature of the active gold species. The vast majority of poly vinyl chloride （PVC） produced globally still uses a mercuric chloride as a cata‐lyst, despite the environmental problems associated with it. Due to the agreement by the Chinese government to remove mercury usage in the PVC industry over the course of the next few years there is an obvious need to find a replacement catalyst;the potential use of gold for this process has been well known for several decades and to date gold seems to be the best candidate for this, pri‐marily due to its superior selectivity when compared to other metals.
