The present article studies the effect of CeO2 and A1203 on the activity of Pd/Co304/cordierite catalyst in conversion of NO, CO, CnHm. The catalysts were characterized by temperature programmed reduction with hydroge...The present article studies the effect of CeO2 and A1203 on the activity of Pd/Co304/cordierite catalyst in conversion of NO, CO, CnHm. The catalysts were characterized by temperature programmed reduction with hydrogen, X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. It is shown that the effect of CeO2 on the properties of Pd/C03 O4/cordierite catalyst depends on preparation method. The catalyst obtained by co-deposition of cerium and cobalt oxides has higher activity in CO oxidation （CO ＋ 02 and CO ＋ NO） and total hexane oxidation （C6H14 ＋ 02）. Such phenomenon is probably caused by more than stoichiometric amount of formed oxygen vacancies, an increase in both mobility of surface oxygen and dispersity of components in the catalytic composition. It is demonstrated that CeO2 addition promotes the SO2 resistance of Pd/C03 O4/cordierite. The second support decreases the activity of Pd/Co3Oa/cordierite catalyst in the reactions of CO and C6H14 with oxygen because of COA1204 formation.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
The term operando was coined at the begin- ning of this century to gather the growing efforts devoted to establish structure-activity relationships by simulta- neously characterizing a catalyst performance and the rel...The term operando was coined at the begin- ning of this century to gather the growing efforts devoted to establish structure-activity relationships by simulta- neously characterizing a catalyst performance and the relevant surface chemistry during genuine catalytic opera- tion. This approach is now widespread and consolidated; it has become an increasingly complex but efficient junction where spectroscopy, materials science, catalysis and engineering meet. While for some characterization techni- ques kinetically relevant reactor cells with good resolution are recently developing, the knowledge gained with magnetic resonance and X-ray and vibrational spectro- scopy studies is already huge and the scope of operando methodology with these techniques is recently expanding from studies with small amounts of powdered solids to more industrially relevant catalytic systems. Engineering catalysis implies larger physical domains, and thus all sort of gradients. Space- and time- resolved multi-technique characterization of both the solid and fluid phases involved in heterogeneous catalytic reactions （including temperature data） is key to map processes from different perspectives, which allows taking into account existing heterogeneities at different scales and facing up- and down-scaling for applications ranging from microstructured reactors to industrial-like macroreactors （operating with shaped catalytic bodies and/or in integral regime）. This work reviews how operando methodology is evolving toward engineered reaction systems.展开更多
The behavior of metallic structured perovskite-based catalysts was evaluated in the combined methane reforming reaction with CO2-O2. The reaction conditions were established by varying the reaction temperature and rea...The behavior of metallic structured perovskite-based catalysts was evaluated in the combined methane reforming reaction with CO2-O2. The reaction conditions were established by varying the reaction temperature and reactor input composition in the range of 650 to 850℃ and CH4/CO2 ratio 1 to 5, respectively. The results of the catalytic tests at 750℃ showed a positive effect of the metallic structure, producing higher conversions and H2/CO ratios in the products compare to that obtained with the powder catalyst.展开更多
Structured catalysts for the simultaneous removal of soot and nitrogen oxides were prepared by means of coating cordierite monoliths with alumina-based suspensions containing Cu, Co or Fe and Cs as the catalytically a...Structured catalysts for the simultaneous removal of soot and nitrogen oxides were prepared by means of coating cordierite monoliths with alumina-based suspensions containing Cu, Co or Fe and Cs as the catalytically active phase. Textural and chemical properties of the coated monoliths were determined by means of N2-physisorption, SEM and temperature programmed reduction. Their activity in the simultaneous removal of soot and NOx was assayed in a lab-scale installation, using a carbon black as diesel surrogate. Catalysts containing Cs exhibited significant activity in deNOx, however soot oxidation activity is poorly enhanced probably due to the low NO2 evolution, pointing to a different NOx adsorption mechanism in the present case, in comparison to previous observations on analogous K and Ba containing catalysts.展开更多
氢燃料电池被认为是未来最有前景的能源技术之一,通过液体甲醇现场重整制氢可有效解决氢气储存和运输等技术瓶颈。文中设计加工了板式微反应器并搭建了配套的制氢系统,制备了具有自还原特性的新型网状CuNi(Fe)/γ-Al 2 O 3/Al结构化催...氢燃料电池被认为是未来最有前景的能源技术之一,通过液体甲醇现场重整制氢可有效解决氢气储存和运输等技术瓶颈。文中设计加工了板式微反应器并搭建了配套的制氢系统,制备了具有自还原特性的新型网状CuNi(Fe)/γ-Al 2 O 3/Al结构化催化剂。以甲醇为原料,实验研究了自制催化剂在微反应器与管式固定床反应器中的催化性能,并与商用CuZn催化剂进行了性能对比。结果表明:与管式反应器相比,微反应器能更好地发挥催化剂的低温活性。开发的CuNiFe结构化催化剂在10000 mL/(g·h)空速下仍能保持82.3%的甲醇转化率,单位质量催化剂的产氢量可达商用催化剂的2.62倍。使用自制催化剂,制氢系统冷态启动40 min可达到甲醇转化率100%的稳定产氢,显著低于使用商用催化剂结果。展开更多
基金supported by the National Specific-Purpose Scientific and Technical Program of Ukraine "Nanotechnology and Nanomaterials" (No.0110U005685)the Program of National Academy of Sciences of Ukraine "Fundamental Problems of Nanos-tructure Systems, Nanomaterials, Nanotechnologies" (No.KPKV 6541030)
文摘The present article studies the effect of CeO2 and A1203 on the activity of Pd/Co304/cordierite catalyst in conversion of NO, CO, CnHm. The catalysts were characterized by temperature programmed reduction with hydrogen, X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. It is shown that the effect of CeO2 on the properties of Pd/C03 O4/cordierite catalyst depends on preparation method. The catalyst obtained by co-deposition of cerium and cobalt oxides has higher activity in CO oxidation （CO ＋ 02 and CO ＋ NO） and total hexane oxidation （C6H14 ＋ 02）. Such phenomenon is probably caused by more than stoichiometric amount of formed oxygen vacancies, an increase in both mobility of surface oxygen and dispersity of components in the catalytic composition. It is demonstrated that CeO2 addition promotes the SO2 resistance of Pd/C03 O4/cordierite. The second support decreases the activity of Pd/Co3Oa/cordierite catalyst in the reactions of CO and C6H14 with oxygen because of COA1204 formation.
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The term operando was coined at the begin- ning of this century to gather the growing efforts devoted to establish structure-activity relationships by simulta- neously characterizing a catalyst performance and the relevant surface chemistry during genuine catalytic opera- tion. This approach is now widespread and consolidated; it has become an increasingly complex but efficient junction where spectroscopy, materials science, catalysis and engineering meet. While for some characterization techni- ques kinetically relevant reactor cells with good resolution are recently developing, the knowledge gained with magnetic resonance and X-ray and vibrational spectro- scopy studies is already huge and the scope of operando methodology with these techniques is recently expanding from studies with small amounts of powdered solids to more industrially relevant catalytic systems. Engineering catalysis implies larger physical domains, and thus all sort of gradients. Space- and time- resolved multi-technique characterization of both the solid and fluid phases involved in heterogeneous catalytic reactions （including temperature data） is key to map processes from different perspectives, which allows taking into account existing heterogeneities at different scales and facing up- and down-scaling for applications ranging from microstructured reactors to industrial-like macroreactors （operating with shaped catalytic bodies and/or in integral regime）. This work reviews how operando methodology is evolving toward engineered reaction systems.
文摘The behavior of metallic structured perovskite-based catalysts was evaluated in the combined methane reforming reaction with CO2-O2. The reaction conditions were established by varying the reaction temperature and reactor input composition in the range of 650 to 850℃ and CH4/CO2 ratio 1 to 5, respectively. The results of the catalytic tests at 750℃ showed a positive effect of the metallic structure, producing higher conversions and H2/CO ratios in the products compare to that obtained with the powder catalyst.
文摘Structured catalysts for the simultaneous removal of soot and nitrogen oxides were prepared by means of coating cordierite monoliths with alumina-based suspensions containing Cu, Co or Fe and Cs as the catalytically active phase. Textural and chemical properties of the coated monoliths were determined by means of N2-physisorption, SEM and temperature programmed reduction. Their activity in the simultaneous removal of soot and NOx was assayed in a lab-scale installation, using a carbon black as diesel surrogate. Catalysts containing Cs exhibited significant activity in deNOx, however soot oxidation activity is poorly enhanced probably due to the low NO2 evolution, pointing to a different NOx adsorption mechanism in the present case, in comparison to previous observations on analogous K and Ba containing catalysts.
