Dry reforming of methane (DRM) can simultaneously convert two critical greenhouse gases CH4 and CO_(2) into high-value syngas. However, the catalyst deactivation caused by sintering and carbon deposition of Ni-based c...Dry reforming of methane (DRM) can simultaneously convert two critical greenhouse gases CH4 and CO_(2) into high-value syngas. However, the catalyst deactivation caused by sintering and carbon deposition of Ni-based catalysts at high temperature is a significant problem to be solved for DRM industrialization. Herein, we represent a hierarchical Ni-La@S-1 catalyst for DRM reaction, showing high anti-sintering/coke capacity to improve DRM stability. The La and Ni nitrates were first grinded into the pores of SBA-15 followed by N2-treatment;the sample was then recrystallized by a unique template assisted-uniformly dispersed strategy to obtain the hierarchical Ni-La@S-1 catalyst. This strategy achieves uniform encapsulation of stabilized Ni-La bimetallic nanoparticles in S-1 with high loading, exhibiting high DRM activity and stability at 700 °C and 36,000 mL·g^(−1)·h^(−1). Moreover, La addition promoted CO_(2) to form bidentate carbonate, a critical intermediate in DRM, which greatly ameliorated carbon deposition in Ni catalysts. This work offers promising clue for tailoring the industrial DRM catalysts.展开更多
采用等体积浸渍法制备了Ni/Al2O3及La改性的Ni-La/Al2O3催化剂,并考察了其浆态床CO甲烷化反应性能。借助XRD、H2-TPR、CO-TPD、H2-TPD等对催化剂进行了表征。结果表明,La助剂改性制备的Ni-La/Al2O3催化剂较Ni/Al2O3催化剂具有更高的CO...采用等体积浸渍法制备了Ni/Al2O3及La改性的Ni-La/Al2O3催化剂,并考察了其浆态床CO甲烷化反应性能。借助XRD、H2-TPR、CO-TPD、H2-TPD等对催化剂进行了表征。结果表明,La助剂改性制备的Ni-La/Al2O3催化剂较Ni/Al2O3催化剂具有更高的CO甲烷化活性,La助剂的添加促进了Ni物种在载体表面的分散,降低了还原温度,增强了催化剂对CO和H2的吸附能力。La助剂的添加次序对甲烷化活性影响较大,采用共浸渍法制备的催化剂具有最佳的甲烷化活性,CO转化率达到96.3%,CH4选择性和时空收率分别达到87.1%和179.6 m L·kg-1·h-1,优于先浸渍Ni后浸渍La或先浸渍La后浸渍Ni制备的催化剂。展开更多
首先制备La掺杂Fe_(78)Si_9B_(13)合金(Fe Si B-La)非晶带材,然后绕制成环型磁芯,在不同温度下进行退火处理,研究La含量和退火温度对其软磁性能的影响。结果表明,随着La含量的增加,Fe Si B-La非晶磁芯的相对起始磁导率μ_i和饱和磁感应...首先制备La掺杂Fe_(78)Si_9B_(13)合金(Fe Si B-La)非晶带材,然后绕制成环型磁芯,在不同温度下进行退火处理,研究La含量和退火温度对其软磁性能的影响。结果表明,随着La含量的增加,Fe Si B-La非晶磁芯的相对起始磁导率μ_i和饱和磁感应强度B_s呈先增大后减小的趋势,而矫顽力H_c呈先减小后增大的趋势。随着退火温度的升高,Fe Si B-La非晶磁芯的μ_i、B_s、H_c、电感L_s和品质因数Q呈先增大后减小的趋势。展开更多
The effect of Au on the reducibility of La Ce Mn catalyst was studied in the synthetic exhaust gas mixture containing 10% oxygen. The characteristics of samples were analyzed by BET, SEM, XRD and activity evaluation...The effect of Au on the reducibility of La Ce Mn catalyst was studied in the synthetic exhaust gas mixture containing 10% oxygen. The characteristics of samples were analyzed by BET, SEM, XRD and activity evaluation. The results show that, in lean combustion, the performance of perovskite type catalysts is evidently enhanced through adding Au, and specially a satisfying reducibility for NO x is demonstrated between 300～500 ℃. The catalytic activity of samples increases with the loading amount of Au, and the maximum conversion rate for NO x decomposition reaches up to 47% in 360～400 ℃. Moreover, the dispersivity and uniformity of the surface distribution of perovskite with Au have an important influence on the catalytic activity.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21776311,22102215,and 22372197)the Natural Science Foundation of Shandong Province,China(No.ZR2023MB101)+4 种基金the Fundamental Research Funds for the Central Universities(Nos.22CX03001A and 21CX06013A)the Taishan Scholar Foundation of Shandong Province(Nos.tspd20210308 and tsqnz20221119)the “111” Program of National College Disciplinary Innovation(No.B13031)the Special Program for Basic Researc of CNPC(No.2023ZZ36)the College Students’ Innovative Entrepreneurial Training Plan Program(No.202403018CX).
文摘Dry reforming of methane (DRM) can simultaneously convert two critical greenhouse gases CH4 and CO_(2) into high-value syngas. However, the catalyst deactivation caused by sintering and carbon deposition of Ni-based catalysts at high temperature is a significant problem to be solved for DRM industrialization. Herein, we represent a hierarchical Ni-La@S-1 catalyst for DRM reaction, showing high anti-sintering/coke capacity to improve DRM stability. The La and Ni nitrates were first grinded into the pores of SBA-15 followed by N2-treatment;the sample was then recrystallized by a unique template assisted-uniformly dispersed strategy to obtain the hierarchical Ni-La@S-1 catalyst. This strategy achieves uniform encapsulation of stabilized Ni-La bimetallic nanoparticles in S-1 with high loading, exhibiting high DRM activity and stability at 700 °C and 36,000 mL·g^(−1)·h^(−1). Moreover, La addition promoted CO_(2) to form bidentate carbonate, a critical intermediate in DRM, which greatly ameliorated carbon deposition in Ni catalysts. This work offers promising clue for tailoring the industrial DRM catalysts.
文摘采用等体积浸渍法制备了Ni/Al2O3及La改性的Ni-La/Al2O3催化剂,并考察了其浆态床CO甲烷化反应性能。借助XRD、H2-TPR、CO-TPD、H2-TPD等对催化剂进行了表征。结果表明,La助剂改性制备的Ni-La/Al2O3催化剂较Ni/Al2O3催化剂具有更高的CO甲烷化活性,La助剂的添加促进了Ni物种在载体表面的分散,降低了还原温度,增强了催化剂对CO和H2的吸附能力。La助剂的添加次序对甲烷化活性影响较大,采用共浸渍法制备的催化剂具有最佳的甲烷化活性,CO转化率达到96.3%,CH4选择性和时空收率分别达到87.1%和179.6 m L·kg-1·h-1,优于先浸渍Ni后浸渍La或先浸渍La后浸渍Ni制备的催化剂。
文摘首先制备La掺杂Fe_(78)Si_9B_(13)合金(Fe Si B-La)非晶带材,然后绕制成环型磁芯,在不同温度下进行退火处理,研究La含量和退火温度对其软磁性能的影响。结果表明,随着La含量的增加,Fe Si B-La非晶磁芯的相对起始磁导率μ_i和饱和磁感应强度B_s呈先增大后减小的趋势,而矫顽力H_c呈先减小后增大的趋势。随着退火温度的升高,Fe Si B-La非晶磁芯的μ_i、B_s、H_c、电感L_s和品质因数Q呈先增大后减小的趋势。
文摘The effect of Au on the reducibility of La Ce Mn catalyst was studied in the synthetic exhaust gas mixture containing 10% oxygen. The characteristics of samples were analyzed by BET, SEM, XRD and activity evaluation. The results show that, in lean combustion, the performance of perovskite type catalysts is evidently enhanced through adding Au, and specially a satisfying reducibility for NO x is demonstrated between 300～500 ℃. The catalytic activity of samples increases with the loading amount of Au, and the maximum conversion rate for NO x decomposition reaches up to 47% in 360～400 ℃. Moreover, the dispersivity and uniformity of the surface distribution of perovskite with Au have an important influence on the catalytic activity.
基金supported by the National Natural Science Foundation of China (21173153)the Science and Technology Department of Science and Technology Support Project of Sichuan Province,China (2011GZ0035)~~
