Monolithic catalysts have been widely investigated for CO_(2) methanation due to their fast mass and heat transfer rate,but the effect of the interaction between the catalyst layer and the monolithic support has been ...Monolithic catalysts have been widely investigated for CO_(2) methanation due to their fast mass and heat transfer rate,but the effect of the interaction between the catalyst layer and the monolithic support has been little studied.In this work,Ni/Al_(2)O_(3)/SiC monolithic catalysts,Ni/Al_(2)O_(3) powder catalysts and Ni/Al_(2)O_(3)/SiC-M catalysts were prepared to explore the effect of Si-Al interaction between the catalyst layer and SiC ceramic for CO_(2) methanation performance.Ni/Al_(2)O_(3)/SiC exhibited a CO_(2) conversion of 53% and a CH_(4) specific reaction rate of 0.05 m mol·g^(-1)·s^(-1) under conditions of 0.1 M Pa,4 00℃,and a WHSV of 60000 ml·g^(-1)·h^(-1).The CO_(2) conversion raised by 0.15-fold and the CH_(4) specific reaction rate raised by 0.25-fold compared to Ni/Al_(2)O_(3) with the same catalyst content.SEM,XRD,Raman,and other characterization results revealed that the formation of Si-Al interaction between the catalyst layer and SiC ceramic could weaken the interaction between Ni and Al_(2)O_(3),thereby improving the catalytic activity of Ni/Al_(2)O_(3)/SiC catalyst.However,the Si-Al interaction was further strengthened during the hightemperature reaction process,which significantly weakened the interaction between Ni and Al_(2)O_(3),thereby leading to a decline in the catalytic performance of Ni/Al_(2)O_(3)/SiC catalyst during an 80-h stability test.This study provides valuable insights for future research and development of monolithic catalysts.展开更多
The rapid solidified process and hot press method were performed to produce three hypereutectic 55%Si-Al, 70%Si-Al and 90%Si-Al alloys for heat dissipation materials. The results show that the atomization is an effect...The rapid solidified process and hot press method were performed to produce three hypereutectic 55%Si-Al, 70%Si-Al and 90%Si-Al alloys for heat dissipation materials. The results show that the atomization is an effective rapid solidified method to produce the Si-Al alloy and the size of atomized Si-Al alloy powder is less than 50 μm. The rapid solidified Si-Al alloy powder were hot pressed at 550 ℃ with the pressure of 700 MPa to obtain the relative densities of 99.4%, 99.2% and 94.4% for 55%Si-Al, 70%Si-Al and 90%Si-Al alloys, respectively. The typical physical properties, such as the thermal conductivity, coefficient of thermal expansion （CTE） and electrical conductivity of rapid solidified Si-Al alloys are acceptable as a heat dissipation material for many semiconductor devices. The 55%Si-Al alloy changes greatly （CTE） with the increase of temperature but obtains a good thermal conductivity. The CTE of 90%Si-Al alloy matches with the silicon very well but its thermal conductivity value is less than 100 W/（m.K）. Therefore, the 70%Si-Al alloy possesses the best comprehensive properties of CTE and thermal conductivity for using as the heat sink materials.展开更多
基金the National Natural Science Foundation of China (22325804 and 22308148)the Natural Science Foundation of Jiangsu Province (BK20230344)the Natural Science Research Project of Jiangsu University (22KJB610001)。
文摘Monolithic catalysts have been widely investigated for CO_(2) methanation due to their fast mass and heat transfer rate,but the effect of the interaction between the catalyst layer and the monolithic support has been little studied.In this work,Ni/Al_(2)O_(3)/SiC monolithic catalysts,Ni/Al_(2)O_(3) powder catalysts and Ni/Al_(2)O_(3)/SiC-M catalysts were prepared to explore the effect of Si-Al interaction between the catalyst layer and SiC ceramic for CO_(2) methanation performance.Ni/Al_(2)O_(3)/SiC exhibited a CO_(2) conversion of 53% and a CH_(4) specific reaction rate of 0.05 m mol·g^(-1)·s^(-1) under conditions of 0.1 M Pa,4 00℃,and a WHSV of 60000 ml·g^(-1)·h^(-1).The CO_(2) conversion raised by 0.15-fold and the CH_(4) specific reaction rate raised by 0.25-fold compared to Ni/Al_(2)O_(3) with the same catalyst content.SEM,XRD,Raman,and other characterization results revealed that the formation of Si-Al interaction between the catalyst layer and SiC ceramic could weaken the interaction between Ni and Al_(2)O_(3),thereby improving the catalytic activity of Ni/Al_(2)O_(3)/SiC catalyst.However,the Si-Al interaction was further strengthened during the hightemperature reaction process,which significantly weakened the interaction between Ni and Al_(2)O_(3),thereby leading to a decline in the catalytic performance of Ni/Al_(2)O_(3)/SiC catalyst during an 80-h stability test.This study provides valuable insights for future research and development of monolithic catalysts.
基金Project (2011) supported by the Hunan Nonferrous Research Funding of Hunan Nonferrous Metals Holding Group Co.,Ltd.,China
文摘The rapid solidified process and hot press method were performed to produce three hypereutectic 55%Si-Al, 70%Si-Al and 90%Si-Al alloys for heat dissipation materials. The results show that the atomization is an effective rapid solidified method to produce the Si-Al alloy and the size of atomized Si-Al alloy powder is less than 50 μm. The rapid solidified Si-Al alloy powder were hot pressed at 550 ℃ with the pressure of 700 MPa to obtain the relative densities of 99.4%, 99.2% and 94.4% for 55%Si-Al, 70%Si-Al and 90%Si-Al alloys, respectively. The typical physical properties, such as the thermal conductivity, coefficient of thermal expansion （CTE） and electrical conductivity of rapid solidified Si-Al alloys are acceptable as a heat dissipation material for many semiconductor devices. The 55%Si-Al alloy changes greatly （CTE） with the increase of temperature but obtains a good thermal conductivity. The CTE of 90%Si-Al alloy matches with the silicon very well but its thermal conductivity value is less than 100 W/（m.K）. Therefore, the 70%Si-Al alloy possesses the best comprehensive properties of CTE and thermal conductivity for using as the heat sink materials.
