In this work,the phosphomolybdate(HPMo)modification strategy was applied to improve the N_(2) selectivity of Mn Co-BTC@SiO_(2)catalyst for the selective catalytic reduction of NO_(x),and further,the mechanism of HPMo ...In this work,the phosphomolybdate(HPMo)modification strategy was applied to improve the N_(2) selectivity of Mn Co-BTC@SiO_(2)catalyst for the selective catalytic reduction of NO_(x),and further,the mechanism of HPMo modification on enhanced catalytic performance was explored.Among Mn Co-BTC@SiO_(2-x) catalysts with different HPMo concentrations,Mn CoBTC@SiO_(2)-0.75 catalyst exhibited not only the highest NH_(3)-SCR performance(95% at 200-300℃)but also the best N_(2)selectivity(exceed 80% at 100-300℃)due to the appropriate redox capacity,greater surface acidity.X-ray photoelectron spectrometer(XPS)and temperature programmed reduction of H_(2)(H_(2)-TPR)results showed that the modification with HPMo reduced the oxidation-reduction performance of the catalyst due to electron transfer from Mo^(5+)to Mn^(4+)/Mn^(3+)and prevent the excessive oxidation of ammonia adsorption species.NH_(3)temperature-programmed desorption of(NH_(3)-TPD)results showed that the modification with HPMo could significantly improve the surface acidity and NH_(3)adsorption,which enhance the catalytic activity and N_(2)selectivity.In-situ diffused reflectance infrared Fourier transform spectroscopy(in-situ DRIFTS)revealed that modification with HPMo increased significantly the amount of adsorbed NH_(3)species on the Bronsted acid site and C_(B)/C_(L),it suppressed the production of N_(2)O by inhibiting the production of NH species,the deep dehydrogenation of ammonia adsorption species.This study provided a simple design strategy for the catalyst to improve the low-temperature catalytic performance and N_(2)selectivity.展开更多
以功能化材料HPMo-SiO2@NH2为固相萃取剂,探究了其对铅的吸附性能,建立了HPMo-SiO2@NH2固相萃取-火焰原子吸收光谱法（FAAS）测定痕量铅的新方法。结果表明：在p H 4.0的条件下,HPMo-SiO2@NH2对Pb^2＋能选择性地定量吸附,富集倍数达到50...以功能化材料HPMo-SiO2@NH2为固相萃取剂,探究了其对铅的吸附性能,建立了HPMo-SiO2@NH2固相萃取-火焰原子吸收光谱法（FAAS）测定痕量铅的新方法。结果表明：在p H 4.0的条件下,HPMo-SiO2@NH2对Pb^2＋能选择性地定量吸附,富集倍数达到50倍,在最佳条件下,方法对铅的检测限（3σ）为1.1μg·L^-1.所建立的新方法成功地用于食物样品中痕量的铅检测,加标回收率为93.5%-104%.展开更多
Achieving a uniform structure with few defects in heavy steel ingot is of high commercial importance. In this present work, in order to verify the potential of pulsed magneto-oscillation(PMO) applied in the production...Achieving a uniform structure with few defects in heavy steel ingot is of high commercial importance. In this present work, in order to verify the potential of pulsed magneto-oscillation(PMO) applied in the production of heavy ingot, an induction coil was located at the hot top of the steel ingot to develop a novel technique, named hot top pulsed magneto oscillation(HPMO). The influences of HPMO on the solidification structure, macro segregation and compactness of a cylindrical medium carbon steel ingot with the weight of 160 kg were systematically investigated by optical microscope(OM) and laser induced breakdown spectroscopy original position metal analyzer(LIBSOPA-100). The results show that HPMO not only causes significant grain refinement and promotes the occurrence of columnar to equiaxed transition(CET) but also can homogenize the carbon distribution and enhance the compactness of the steel ingot. Therefore, HPMO technique has the potential to be applied in the production of heavy steel ingots on an industrial scale.展开更多
A new multi-shelled hollow mesoporous organosilica(M-HPMO)bearing thiol moieties on dual surfaces of the pore has been prepared.M-HPMO exhibits simultaneous removal of Hg(II),Cr(VI),and Pb(II)from water with fast adso...A new multi-shelled hollow mesoporous organosilica(M-HPMO)bearing thiol moieties on dual surfaces of the pore has been prepared.M-HPMO exhibits simultaneous removal of Hg(II),Cr(VI),and Pb(II)from water with fast adsorption kinetics(C_(0)=32_(0)mg L^(−1),equilibrium within 5 min)and ultrahigh adsorption capacities of 99_(0).19,877.19,and 826.45 mg g^(−1).展开更多
基金supported by the National Natural Science Foundation of China(No.U20A20130 and 21806009)the Fundamental Research Funds for the Central Universities(No.FRF-IDRY-19-020)。
文摘In this work,the phosphomolybdate(HPMo)modification strategy was applied to improve the N_(2) selectivity of Mn Co-BTC@SiO_(2)catalyst for the selective catalytic reduction of NO_(x),and further,the mechanism of HPMo modification on enhanced catalytic performance was explored.Among Mn Co-BTC@SiO_(2-x) catalysts with different HPMo concentrations,Mn CoBTC@SiO_(2)-0.75 catalyst exhibited not only the highest NH_(3)-SCR performance(95% at 200-300℃)but also the best N_(2)selectivity(exceed 80% at 100-300℃)due to the appropriate redox capacity,greater surface acidity.X-ray photoelectron spectrometer(XPS)and temperature programmed reduction of H_(2)(H_(2)-TPR)results showed that the modification with HPMo reduced the oxidation-reduction performance of the catalyst due to electron transfer from Mo^(5+)to Mn^(4+)/Mn^(3+)and prevent the excessive oxidation of ammonia adsorption species.NH_(3)temperature-programmed desorption of(NH_(3)-TPD)results showed that the modification with HPMo could significantly improve the surface acidity and NH_(3)adsorption,which enhance the catalytic activity and N_(2)selectivity.In-situ diffused reflectance infrared Fourier transform spectroscopy(in-situ DRIFTS)revealed that modification with HPMo increased significantly the amount of adsorbed NH_(3)species on the Bronsted acid site and C_(B)/C_(L),it suppressed the production of N_(2)O by inhibiting the production of NH species,the deep dehydrogenation of ammonia adsorption species.This study provided a simple design strategy for the catalyst to improve the low-temperature catalytic performance and N_(2)selectivity.
文摘以功能化材料HPMo-SiO2@NH2为固相萃取剂,探究了其对铅的吸附性能,建立了HPMo-SiO2@NH2固相萃取-火焰原子吸收光谱法（FAAS）测定痕量铅的新方法。结果表明：在p H 4.0的条件下,HPMo-SiO2@NH2对Pb^2＋能选择性地定量吸附,富集倍数达到50倍,在最佳条件下,方法对铅的检测限（3σ）为1.1μg·L^-1.所建立的新方法成功地用于食物样品中痕量的铅检测,加标回收率为93.5%-104%.
基金financially supported by the National Natural Science Foundation of China(Granted No.U1760204,51504048)the National Key Research Program of China(Granted No.2017YFB0701800)
文摘Achieving a uniform structure with few defects in heavy steel ingot is of high commercial importance. In this present work, in order to verify the potential of pulsed magneto-oscillation(PMO) applied in the production of heavy ingot, an induction coil was located at the hot top of the steel ingot to develop a novel technique, named hot top pulsed magneto oscillation(HPMO). The influences of HPMO on the solidification structure, macro segregation and compactness of a cylindrical medium carbon steel ingot with the weight of 160 kg were systematically investigated by optical microscope(OM) and laser induced breakdown spectroscopy original position metal analyzer(LIBSOPA-100). The results show that HPMO not only causes significant grain refinement and promotes the occurrence of columnar to equiaxed transition(CET) but also can homogenize the carbon distribution and enhance the compactness of the steel ingot. Therefore, HPMO technique has the potential to be applied in the production of heavy steel ingots on an industrial scale.
基金financially supported by the National Natural Science Foundation of China(52304072)funded by the Shandong Postdoctora1 Science Foundation(SDBX2023019)+1 种基金the Fundamental Research Funds for the Central Universities(23CX06022A)the Applied Research Project of Qingdao Postdoctoral Researchers(QDBSH20230202010).
文摘A new multi-shelled hollow mesoporous organosilica(M-HPMO)bearing thiol moieties on dual surfaces of the pore has been prepared.M-HPMO exhibits simultaneous removal of Hg(II),Cr(VI),and Pb(II)from water with fast adsorption kinetics(C_(0)=32_(0)mg L^(−1),equilibrium within 5 min)and ultrahigh adsorption capacities of 99_(0).19,877.19,and 826.45 mg g^(−1).
