Study On The Catalytic Performance And Mass Spectra Signal Enhancement Effect Of Graphene Oxide

Due to the wide variety of sources,cheap price,biological compatibility,easy to modify,environment friendly,carbon-based materials examplified by graphene have shown unique catalytic performance in the field of organic synthesis.However,conventional exploration process usually needs long time and complicated steps,which is not only inefficient,but also lacks intuitive and reliable understanding for the catalytic mechanism and active sites.Fortunately,desorption electrospray ionization mass spectrometry(DESI-MS)makes up those disadvantages perfectly.DESI-MS has pioneered a new era of ambient ionization mass spectrometry and expanded the application of mass spectrometry in many aspects greatly.As a result of direct ionization at atmospheric pressure,DESI-MS can not only detect and analyze samples efficiently,but also in situ characterize the synthetic products and monitor chemical reactions quickly.At present,significant breakthrough has been made in organic reaction system by DESI-MS,including the types of reaction,possible intermediates,and the factors contributing to the reaction acceleration in the microdroplets.Carbon materials have attracted much attention due to their unique physicochemical properties,whereas,there are few literatures about the application of carbon materials in the organic reaction explored by AMS,especially in the study of GO's performance with the aid of DESI-MS.In this paper,the Friedel-Crafts Alkylation reaction of aromatic alcohols with the participation of GO was studied by DESI-MS.Under the catalysis of oxygen-containing functional groups on the surface of GO,especially carboxylic acid groups,aromatic alcohol undergoes an intermolecular Friedel-Crafts Alkylation reaction,rather than traditionally reported oxidation,dehydration or polymerization reactions.Our work also found that GO has a significant enhancement effect on the DESI-MS mass spectrometry signal of samples with weak ionization capacity or low concentration.With the help of GO,we detected the intermediates in Schiff base synthesis reactions.In conclusion,we evaluated the surface catalyetic activity of GO and its performance in the mass spectrum signal enhancement effect through in situ DESI-MS technology,which have provided support for understanding and broadening the application of carbon-based materials in catalysis and analysis,and broadened our perspective with respect to solving the core scientific issues of organic chemistry.