In this paper the effect of catalyst and carrier in electric field enhanced plasma on methane conversion into C2 hydrocarbons was investigated. Methane coupling reaction was studied in the system of continuous flow r...In this paper the effect of catalyst and carrier in electric field enhanced plasma on methane conversion into C2 hydrocarbons was investigated. Methane coupling reaction was studied in the system of continuous flow reactor on Ni, MoO3, MnO2 catalysts and different ZSM-5 carriers. The per pass conversion of methane can be as high as 22%, the selectivity of ethylene can be as high as 23.8%, of acetylene 60.8%, of ethane 5.4% and of total C2 hydrocarbons was more than 90%. ZSM-5-25 was the better carrier and MnO2 was the better active component. The efficiency of energy was as high as 7.81%.展开更多
In terms of the reaction of COreduction to CO with hydrogen, COconversion is very low at low temperature due to the limitation of thermodynamic equilibrium（TE）. To overcome this limitation, plasma catalytic reductio...In terms of the reaction of COreduction to CO with hydrogen, COconversion is very low at low temperature due to the limitation of thermodynamic equilibrium（TE）. To overcome this limitation, plasma catalytic reduction of COto CO in a catalyst-filled dielectric barrier discharge（DBD） reactor is studied. An enhanced effect of plasma on the reaction over Au/CeOcatalysts is observed. For both the conventionally catalytic（CC） and plasma catalytic（PC, Pin= 15 W） reactions under conditions of 400 °C, H/CO= 1,200 SCCM, GHSV = 12,000 mL·gcat·h, COconversions over Au/CeOreach 15.4% and 25.5% due to the presence of Au, respectively, however, those over CeOare extremely low and negligible. Moreover,COconversion over Au/CeOin the PC reaction exceeds 22.4% of the TE conversion. Surface intermediate species formed on the catalyst samples during the reactions are determined by in-situ temperatureprogrammed decomposition（TPD） technique. Interestingly, it disclosed that in the PC reaction, the formation of formate intermediate is enhanced by plasma, and the acceleration by plasma in the decomposition of formate species is much greater than that in the formation of formate species on Au/CeO. Enhancement factor is introduced to quantify the enhanced effect of plasma. Lower reactor temperature, higher gas hourly space velocity（GHSV）, and lower molar ratio of H/COwould be associated with larger enhancement factor.展开更多
In this work,a single Al_(2)O_(3) particle packed dielectric barrier discharge(DBD)reactor with adjustable discharge gap is built,and the influences of the particle shape(ball and column)and the residual gap between t...In this work,a single Al_(2)O_(3) particle packed dielectric barrier discharge(DBD)reactor with adjustable discharge gap is built,and the influences of the particle shape(ball and column)and the residual gap between the top electrode and particle on the electrical and optical characteristics of plasma are studied.Our research confirms that streamer discharge and surface discharge are the two main discharge patterns in the single-particle packed DBD reactor.The strong electric field distortion at the top of the ball or column caused by the dielectric polarization effect is an important reason for the formation of streamer discharge.The length of streamer discharge is proportional to the size of the residual gap,but the number of discharge times of a single voltage cycle shows an opposite trend.Compared to the column,a smooth spherical surface is more conducive to the formation of large and uniform surface discharges.The surface discharge area and the discharge intensity reach a maximum when the gap is equal to the diameter of the ball.All in all,the results of this study will provide important theoretical support for the establishment of the synergistic characteristics of discharge and catalysis in plasma catalysis.展开更多
基金Supports from the National Natural Science Foundation of China(No 29776037)
文摘In this paper the effect of catalyst and carrier in electric field enhanced plasma on methane conversion into C2 hydrocarbons was investigated. Methane coupling reaction was studied in the system of continuous flow reactor on Ni, MoO3, MnO2 catalysts and different ZSM-5 carriers. The per pass conversion of methane can be as high as 22%, the selectivity of ethylene can be as high as 23.8%, of acetylene 60.8%, of ethane 5.4% and of total C2 hydrocarbons was more than 90%. ZSM-5-25 was the better carrier and MnO2 was the better active component. The efficiency of energy was as high as 7.81%.
基金supported by the National Natural Science Foundation of China(21673030)the Fundamental Research Funds for the Central Universities(DUT16QY49)
文摘In terms of the reaction of COreduction to CO with hydrogen, COconversion is very low at low temperature due to the limitation of thermodynamic equilibrium（TE）. To overcome this limitation, plasma catalytic reduction of COto CO in a catalyst-filled dielectric barrier discharge（DBD） reactor is studied. An enhanced effect of plasma on the reaction over Au/CeOcatalysts is observed. For both the conventionally catalytic（CC） and plasma catalytic（PC, Pin= 15 W） reactions under conditions of 400 °C, H/CO= 1,200 SCCM, GHSV = 12,000 mL·gcat·h, COconversions over Au/CeOreach 15.4% and 25.5% due to the presence of Au, respectively, however, those over CeOare extremely low and negligible. Moreover,COconversion over Au/CeOin the PC reaction exceeds 22.4% of the TE conversion. Surface intermediate species formed on the catalyst samples during the reactions are determined by in-situ temperatureprogrammed decomposition（TPD） technique. Interestingly, it disclosed that in the PC reaction, the formation of formate intermediate is enhanced by plasma, and the acceleration by plasma in the decomposition of formate species is much greater than that in the formation of formate species on Au/CeO. Enhancement factor is introduced to quantify the enhanced effect of plasma. Lower reactor temperature, higher gas hourly space velocity（GHSV）, and lower molar ratio of H/COwould be associated with larger enhancement factor.
基金the National Key R&D Program of China(No.2021YFF0603100)the Natural Science Foundation of Jiangsu Province(No.BK20200452)+1 种基金the Postdoctoral Research Foundation of China(No.2020M681584)National Natural Science Foundation of China(No.51977110)。
文摘In this work,a single Al_(2)O_(3) particle packed dielectric barrier discharge(DBD)reactor with adjustable discharge gap is built,and the influences of the particle shape(ball and column)and the residual gap between the top electrode and particle on the electrical and optical characteristics of plasma are studied.Our research confirms that streamer discharge and surface discharge are the two main discharge patterns in the single-particle packed DBD reactor.The strong electric field distortion at the top of the ball or column caused by the dielectric polarization effect is an important reason for the formation of streamer discharge.The length of streamer discharge is proportional to the size of the residual gap,but the number of discharge times of a single voltage cycle shows an opposite trend.Compared to the column,a smooth spherical surface is more conducive to the formation of large and uniform surface discharges.The surface discharge area and the discharge intensity reach a maximum when the gap is equal to the diameter of the ball.All in all,the results of this study will provide important theoretical support for the establishment of the synergistic characteristics of discharge and catalysis in plasma catalysis.
