Preparation of highly active hydrodesulfurization catalysts is extremely meaningful for the sulfur removal from thiophene substances.In this work,commercial nano-Al_(2)O_(3)with mesoporous structure supported monometa...Preparation of highly active hydrodesulfurization catalysts is extremely meaningful for the sulfur removal from thiophene substances.In this work,commercial nano-Al_(2)O_(3)with mesoporous structure supported monometallic phosphide(NiP/Al_(2)O_(3)and MoP/Al_(2)O_(3))and bimetallic phosphide(NiMoP/Al_(2)O_(3)with various Ni/Mo molar ratio)catalysts are successfully prepared by temperature-programmed reduction.X-ray diffraction(XRD)result shows the Ni/Mo molar ratio affect the crystal phase in catalysts.Scanning electron microscopy(SEM),transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS)characterizations co-confirm the interact between Ni and Mo elements in bimetallic phosphide.Catalyst evaluation in hydrodesulfurization of dibenzothiophene shows that bimetallic phosphide samples exhibit better catalytic performance than monometallic phosphide.62.1%conversion and 86.3%biphenyl selectivity with 30 h stability are achieved over NiMoP/Al_(2)O_(3)(Ni/Mo=1∶1)catalyst at 400℃under 3 MPa H_(2).All characterization results demonstrate that the improved activity of bimetallic phosphide owes to the Ni-Mo synergistic effect in NiMoP/Al_(2)O_(3)(Ni/Mo=1∶1)catalyst.This finding provides a guide to the design of bimetallic catalyst with synergistic effect.展开更多
Atomic electronegativity interaction vector (AEIV) and atomic hybridization state index (AHSI) were used for establishing the quantitative structure-spectroscopy relationship(QSSR) model of 13C NMR chemical shifts of ...Atomic electronegativity interaction vector (AEIV) and atomic hybridization state index (AHSI) were used for establishing the quantitative structure-spectroscopy relationship(QSSR) model of 13C NMR chemical shifts of isodon diterpenoid compounds.Multiple linear regression (MLR) and computational neural network (CNN) were used to create the models,and the estimation stability and generalization ability of the models were strictly analyzed by both internal and external validations.The established MLR and CNN models were correlated with experimental values and the correlation coefficients of model estimation,leave-one-out (LOO)cross-validation (CV),and predicted values of external samples were Rcum=0.9724,RCV=0.9723,Qext=0.9738 (MLR);Rcum=0.9957,Qext=0.9956 (CNN),respectively.The results indicated that CNN gave significantly better prediction of 13C NMR chemical shifts for isodon diterpenoids than MLR.Satisfactory results showed that AEIV and AHSI were obviously good for modeling 13C NMR chemical shifts of isodon diterpenoid compounds.展开更多
基金supported by National Natural Science Foundation of China(22202093)the Scientific and Technological Innovation Youth Talent Team of Shanxi Province(202204051001005)。
文摘Preparation of highly active hydrodesulfurization catalysts is extremely meaningful for the sulfur removal from thiophene substances.In this work,commercial nano-Al_(2)O_(3)with mesoporous structure supported monometallic phosphide(NiP/Al_(2)O_(3)and MoP/Al_(2)O_(3))and bimetallic phosphide(NiMoP/Al_(2)O_(3)with various Ni/Mo molar ratio)catalysts are successfully prepared by temperature-programmed reduction.X-ray diffraction(XRD)result shows the Ni/Mo molar ratio affect the crystal phase in catalysts.Scanning electron microscopy(SEM),transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS)characterizations co-confirm the interact between Ni and Mo elements in bimetallic phosphide.Catalyst evaluation in hydrodesulfurization of dibenzothiophene shows that bimetallic phosphide samples exhibit better catalytic performance than monometallic phosphide.62.1%conversion and 86.3%biphenyl selectivity with 30 h stability are achieved over NiMoP/Al_(2)O_(3)(Ni/Mo=1∶1)catalyst at 400℃under 3 MPa H_(2).All characterization results demonstrate that the improved activity of bimetallic phosphide owes to the Ni-Mo synergistic effect in NiMoP/Al_(2)O_(3)(Ni/Mo=1∶1)catalyst.This finding provides a guide to the design of bimetallic catalyst with synergistic effect.
文摘Atomic electronegativity interaction vector (AEIV) and atomic hybridization state index (AHSI) were used for establishing the quantitative structure-spectroscopy relationship(QSSR) model of 13C NMR chemical shifts of isodon diterpenoid compounds.Multiple linear regression (MLR) and computational neural network (CNN) were used to create the models,and the estimation stability and generalization ability of the models were strictly analyzed by both internal and external validations.The established MLR and CNN models were correlated with experimental values and the correlation coefficients of model estimation,leave-one-out (LOO)cross-validation (CV),and predicted values of external samples were Rcum=0.9724,RCV=0.9723,Qext=0.9738 (MLR);Rcum=0.9957,Qext=0.9956 (CNN),respectively.The results indicated that CNN gave significantly better prediction of 13C NMR chemical shifts for isodon diterpenoids than MLR.Satisfactory results showed that AEIV and AHSI were obviously good for modeling 13C NMR chemical shifts of isodon diterpenoid compounds.
