Nanocrystalline LaFeO3 was synthesised by the citrate method with La(NO3)3·6H2O,Fe(NO3)3·9H2O and citric acid as the raw materials. Before and after reduction, its structure was characterized by means of X r...Nanocrystalline LaFeO3 was synthesised by the citrate method with La(NO3)3·6H2O,Fe(NO3)3·9H2O and citric acid as the raw materials. Before and after reduction, its structure was characterized by means of X ray diffraction and transmission electron microscopy(TEM). And after reduction of LaFeO3 oxide, the rareearth oxide, La2O3, prevents Fe particles from agglomerating and promotes the dispersion of nano scale Fe particles (ca.40nm), which is one of the key factors for the growth of carbon nanotube. The carbon nanotubes from the catalytic decomposition of C2H2 were obtained using Fe/La2O3 nano scale catalyst, which wasformed from LaFeO3 oxide as the catalyst precursor. The morphological structures of the carbon nanotube obtained have been examined by TEM. The results indicate that they are multi walled nanotubes of good quality with inter diameter ranging from 20～25nm and length ranging from 25～40μm. The yields of carbon nanotube are 1.25g·gcat-1 at the reaction temperature of 973K for 30min.展开更多
As a rapid uniform and efficient heating method, microwave irradiation has been widely used in chemical reaction and preparing nanomaterials. Here Pt/carbon nanotube(CNT) catalysts with w(Pt)=18.1% and 9.4 % were rapi...As a rapid uniform and efficient heating method, microwave irradiation has been widely used in chemical reaction and preparing nanomaterials. Here Pt/carbon nanotube(CNT) catalysts with w(Pt)=18.1% and 9.4 % were rapidly synthesized by microwave irradiation heating polyol process and employing the ethylene glycol solution of H 2PtCl 6 as the precursors in the presence of CNT support. TEM imaging showed that microwave-prepared Pt nanoparticles were very uniform in size, with an average size of 3.1 nm, and uniformly dispersed on the CNT surface. Electrochemical experiments demonstrated that microwave-synthesized Pt/CNT catalysts exhibited a higher catalytic activity for electrooxidation of liquid methanol than E-TEK Pt/C. The significant improvement in catalyst performance derives from that microwave-synthesized Pt nanoparticles have a uniform small particle size and uniforml dispersion on the CNT surface.展开更多
文摘Nanocrystalline LaFeO3 was synthesised by the citrate method with La(NO3)3·6H2O,Fe(NO3)3·9H2O and citric acid as the raw materials. Before and after reduction, its structure was characterized by means of X ray diffraction and transmission electron microscopy(TEM). And after reduction of LaFeO3 oxide, the rareearth oxide, La2O3, prevents Fe particles from agglomerating and promotes the dispersion of nano scale Fe particles (ca.40nm), which is one of the key factors for the growth of carbon nanotube. The carbon nanotubes from the catalytic decomposition of C2H2 were obtained using Fe/La2O3 nano scale catalyst, which wasformed from LaFeO3 oxide as the catalyst precursor. The morphological structures of the carbon nanotube obtained have been examined by TEM. The results indicate that they are multi walled nanotubes of good quality with inter diameter ranging from 20～25nm and length ranging from 25～40μm. The yields of carbon nanotube are 1.25g·gcat-1 at the reaction temperature of 973K for 30min.
文摘As a rapid uniform and efficient heating method, microwave irradiation has been widely used in chemical reaction and preparing nanomaterials. Here Pt/carbon nanotube(CNT) catalysts with w(Pt)=18.1% and 9.4 % were rapidly synthesized by microwave irradiation heating polyol process and employing the ethylene glycol solution of H 2PtCl 6 as the precursors in the presence of CNT support. TEM imaging showed that microwave-prepared Pt nanoparticles were very uniform in size, with an average size of 3.1 nm, and uniformly dispersed on the CNT surface. Electrochemical experiments demonstrated that microwave-synthesized Pt/CNT catalysts exhibited a higher catalytic activity for electrooxidation of liquid methanol than E-TEK Pt/C. The significant improvement in catalyst performance derives from that microwave-synthesized Pt nanoparticles have a uniform small particle size and uniforml dispersion on the CNT surface.
