Effects Of Transition Metal Materials On The Hydrothermal Synthesis Of Pyridine Bases And The Degradation Of Trichloroethylene

Pyridine bases including pyridine and its derivatives, which are all importantraw materials in fine chemical industry. There are mainly about two ways to getpyridine bases: one is separation from coal tar and the other is chemical synthesis.Because of the disadvantages (such as low productivity, poor quality, expensive, etc)combined with the change of energy structure, the tar extraction almost becomesobsolete. The chemical synthesis of pyridine bases is realized by the reaction ofammonia with aldehydes, ketones, alcohols, alkenes, alkynes and so on. Due to theurgency of the green production and the rise of biomass ethanol, alcohol/ammoniamethod will become an important direction of pyridine bases synthesis.Transitionmetal materials play a crucial role in the catalytic synthesis of pyridine bases whilethey are easily accessible and environmental friendly. The development for efficientcatalysts has become the key point of alcohol/ammonia method.Based on the background above, in this paper5-ethyl-2-methyl pyridine (EMP)was synthesized under hydrothermal condition with cheap and environmentalfriendly raw materials, such as ethanol and ammonium bicarbonate, transition metalmaterials (cuprous oxide) as catalyst and oxidant. The parameters which affected theyield of EMP were well discussed to optimize the experimental conditions. Theoptional experimental condition was: NH4HCO313mmol,C2H5OH100mmol,deionized H2O12.20mL, Cu2O4mmol,240℃for5d. At the same time,preliminary study was made on the mechanism of the synthesis of EMP fromethanol and ammonia. We assumed that the ethanol was firstly oxidized toacetaldehyde, and then formed EMP with ammonia in the following step.Chlorinated organics in soil and groundwater are serious environmentalpollutants and they do harm to human beings, animals and other living beings. Because of its good hydrogenation and unique empty track structure, transitionmetal materials are very efficient in dechlorination of chlorinated organics. Recently,there are a lot of studies focused on the remediation of chlorinated compounds withzero-valent iron. Nowadays, researchers have paid more attention to theperformance and potential application of nanoscale zero-valent iron (nZVI) andnZVI-based multicomponent nanoparticles. However nanoparticles are prone toagglomeration，which usually result in a decreased activity. To overcome theaforementioned shortcomings, an effective strategy is to immobilize or stabilizenZVI or nZVI-based bimetals within various supports. This technology has becomea research hotspot in the field of TCE dechlorination.Based on the background above, in this paper we designed to synthesize SiO2coating Fe/FeS nanoparticles (Fe/FeS@SiO2) and carbon sphere encapsulatingnanoscale zero-valent Fe/Ni (nZV-Fe/Ni@CS). The morphology, composition andstructure of the nanoparticles are investigated by XRD, SEM, TEM, XPS and etc.The two newly synthesized catalysts all showed good performances in thedechlorination of TCE.