Magnetic starch microspheres(AAM-MSM)were synthesized via an inverse emulsion graft copolymerization by using mechanically activated cassava starch(MS)as a crude material,acrylic acid(AA)and acrylamide(AM)as graft cop...Magnetic starch microspheres(AAM-MSM)were synthesized via an inverse emulsion graft copolymerization by using mechanically activated cassava starch(MS)as a crude material,acrylic acid(AA)and acrylamide(AM)as graft copolymer monomers,and methyl methacrylate(MMA)as the dispersing agent and used as an adsorbent for the removal of Cd(Ⅱ)ions from aqueous solution.Fourier-transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),and vibrating sample magnetometry(VSM)were used to characterize the AAM-MSM adsorbent.The results indicated that AA,AM,and MMA were grafted to the MS,and the Fe_(3)O_(4) nanoparticles were encapsulated in the AAM-MSM adsorbent microspheres.The adsorbent exhibited a smooth surface,uniform size,and good sphericity because of the addition of the MMA and provided more adsorption sites for the Cd(Ⅱ)ions.The maximum adsorption capacity of Cd(Ⅱ)on the AAM-MSM was 39.98 mg·g^(-1).The adsorbents were superparamagnetic,and the saturation magnetization was 16.7 A·m^(2)·kg^(-1).Additionally,the adsorption isotherms and kinetics of the adsorption process were further investigated.The process of Cd(Ⅱ)ions adsorbed onto the AAM-MSM could be described more favorably by the pseudo-second-order kinetic and Langmuir isothermal adsorption models,which suggested that the chemical reaction process dominated the adsorption process for the Cd(Ⅱ)and chemisorption was the rate-controlling step during the Cd(Ⅱ)removal process.展开更多
The dry reforming of methane(DRM)reaction can directly convert methane(CH_(4))and carbon dioxide(CO_(2))into syngas(H_(2)+CO),which is a promising method for achieving carbon neutralization.In this study,a series of 3...The dry reforming of methane(DRM)reaction can directly convert methane(CH_(4))and carbon dioxide(CO_(2))into syngas(H_(2)+CO),which is a promising method for achieving carbon neutralization.In this study,a series of 3Ni-xCo/Mg1HAP alloy catalysts with different ratio were synthesized by the coprecipitation method,and the optimum Ni-Co ratio for the DRM reaction was studied.A series of characterization methods revealed that after Co was added,the formation of Ni-Co alloys increased the interactions between metals.However,an excess of Co inhibits the entry of Ni into the lattice of Mg_(1)HAP,resulting in metal accumulation on the surface of the support.In addition,the introduction of Co improves the dispersion of Ni metal,which endows the catalyst with better catalytic activity and stability.Raman spectroscopy of the catalyst after the stability test showed that the addition of Co reduced the proportion of graphitic carbon,which was also the main reason for its improved stability.展开更多
基金This work was supported by the National Natural Science Foundation of China(21766001,21961160741)Guangxi Natural Science Foundation of China(2018GXNSFAA281342)+1 种基金the Dean Project of Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology(2018Z009)Special funding for"Guangxi Bagui Scholars".
文摘Magnetic starch microspheres(AAM-MSM)were synthesized via an inverse emulsion graft copolymerization by using mechanically activated cassava starch(MS)as a crude material,acrylic acid(AA)and acrylamide(AM)as graft copolymer monomers,and methyl methacrylate(MMA)as the dispersing agent and used as an adsorbent for the removal of Cd(Ⅱ)ions from aqueous solution.Fourier-transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),and vibrating sample magnetometry(VSM)were used to characterize the AAM-MSM adsorbent.The results indicated that AA,AM,and MMA were grafted to the MS,and the Fe_(3)O_(4) nanoparticles were encapsulated in the AAM-MSM adsorbent microspheres.The adsorbent exhibited a smooth surface,uniform size,and good sphericity because of the addition of the MMA and provided more adsorption sites for the Cd(Ⅱ)ions.The maximum adsorption capacity of Cd(Ⅱ)on the AAM-MSM was 39.98 mg·g^(-1).The adsorbents were superparamagnetic,and the saturation magnetization was 16.7 A·m^(2)·kg^(-1).Additionally,the adsorption isotherms and kinetics of the adsorption process were further investigated.The process of Cd(Ⅱ)ions adsorbed onto the AAM-MSM could be described more favorably by the pseudo-second-order kinetic and Langmuir isothermal adsorption models,which suggested that the chemical reaction process dominated the adsorption process for the Cd(Ⅱ)and chemisorption was the rate-controlling step during the Cd(Ⅱ)removal process.
基金supported by the Guangxi Natural Science Foundation(2020GXNSFDA297007)the National Natural Science Foundation of China(22078074)the Special Funding for‘Guangxi Bagui Scholars’.
文摘The dry reforming of methane(DRM)reaction can directly convert methane(CH_(4))and carbon dioxide(CO_(2))into syngas(H_(2)+CO),which is a promising method for achieving carbon neutralization.In this study,a series of 3Ni-xCo/Mg1HAP alloy catalysts with different ratio were synthesized by the coprecipitation method,and the optimum Ni-Co ratio for the DRM reaction was studied.A series of characterization methods revealed that after Co was added,the formation of Ni-Co alloys increased the interactions between metals.However,an excess of Co inhibits the entry of Ni into the lattice of Mg_(1)HAP,resulting in metal accumulation on the surface of the support.In addition,the introduction of Co improves the dispersion of Ni metal,which endows the catalyst with better catalytic activity and stability.Raman spectroscopy of the catalyst after the stability test showed that the addition of Co reduced the proportion of graphitic carbon,which was also the main reason for its improved stability.
