Study On Preparation Of Transition Metal Phosphide By Resin Carbonization

Transition metal phosphides are widely used in various fields（photonics,magnetism,electronics,catalysis and so on）.In particular,due to the unique structure of them,transition metal phosphides have shown high catalytic activities for several reactions such as hydrogenation and hydrotreating,N₂H₄decomposition and NO reduction.these materials have attracted considerable attention for recent years.With the development of metal phosphide materials in various application fields,more and more efforts have been focused on synthetic methods for preparing metal phosphides.However,most of the current methods require high temperature and high pressure,some need toxic substances,and some are relatively difficult to operate.Therefore,it is of great significance to develop a simple,convenient and green synthetic route.Therefore,in this paper,transition metal phosphides were successfully synthesized by carbothermal reduction and resin as carbon source,and their formation mechanism was studied.1.MoP/H-ZSM-5 and Ni₂P/H-ZSM-5 were synthesized using H-ZSM-5as carrier and anion exchange resin（D201）as carbon source under inert gas conditions.And study its formation mechanism.（1）MoP/H-ZSM-5 was synthesized from ammonium molybdate,diammonium hydrogen phosphate,D201 and H-ZSM-5 by carbothermal reduction under argon（Ar）gas stream.The effect of temperature on the synthesis of supported MoP was studied.The results showed that pure phase MoP/H-ZSM-5 catalyst could be synthesized only when the temperature reached 900 ℃.（2）Ni₂P/H-ZSM-5 was synthesized from nickel nitrate,diammonium hydrogen phosphate,D201 and H-ZSM-5 by carbothermal reduction in Ar gas stream.The influence of temperature and Ni/P molar ratio on the preparation of pure phase Ni₂P was studied.The results showed that pure phase Ni₂P/H-ZSM-5 can be obtained when the molar ratio of Ni:P is 1.5 and temperature is 900 ℃.（3）The formation mechanism was proposed by thermogravimetry-mass spectrometry（TG-MS）and X-ray diffraction（XRD）.D201 resin is carbonized to produce C and H₂,and a small portion of Mo/Ni and PO_x species are firstly reduced by H₂ and then the rest are reduced by C,to produce MoP/Ni₂P on the H-ZSM-5,with the release of H₂O,CO and CO₂.2.Co₂P,Ni₂P and Fe₂P were synthesized by using phenolic resin（PFR）as carbon source in inert gas at 900 ℃.The formation mechanism of final phosphating products was explained.（1）Co₂P was synthesized from cobalt nitrate hexahydrate,diammonium hydrogen phosphate and phenolic resin（PFR）by carbothermal reduction in argon（Ar）gas stream.The pure phase Co₂P can be synthesized when the molar ratio of Co:P is 2 and the mass ratio of PFR:Co is 2.3.（2）Ni₂P was synthesized from nickel nitrate,diammonium hydrogen phosphate and phenolic resin（PFR）by carbothermal reduction in Ar gas stream.The pure phase Ni₂P can be obtained when the molar ratio of Ni:P is 1and the mass ratio of PFR:Ni is 2.3.（3）Fe₂P was synthesized from iron nitrate,diammonium hydrogen phosphate and phenolic resin（PFR）by carbothermal reduction in Ar gas stream.The results show that when the molar ratio of Fe:P is 2 and the mass ratio of PFR:Fe is 3.5,the products of Fe₂P with very small impurities can be obtained after treatment.（4）The formation mechanism of Co₂P,Ni₂P and Fe₂P was proposed by thermogravimetric-mass spectrometry（TG-MS）,X-ray diffraction（XRD）,SEM,TEM and Carbon content analysis.PFR carbonizes to form C,H₂,CH₄and H₂O,then a small number of Co/Ni/Fe and PO_x species are first reduced by H₂,and the rest are reduced by C to produce Co₂P/Ni₂P/Fe₂P,with the release of a large amount of H₂O,CO and CO₂.