A novel proton-gradient-transfer acid complexes as an efficient and reusable catalyst for fatty acid esterification

In this work,a series of novel proton-gradient-transfer acid complexes(PGTACs)were developed.Their physicochemical properties,including thermal stability,melting point,and Hammett acidity,were measured.The effects of catalyst loading,reaction temperature,and substrate expansion on the catalytic performance were systematically studied.It is found that the combination of bidentate N-heterocycle and H;SO;(1:2 M ratio)could form simultaneously N–H covalent bond and N…H hydrogen bond,which makes the PGTACs excellent catalysts integrate the advantages of strong acids(high catalytic activity)and ionic liquids(phase separation)in the esterification reaction.Moreover,these PGTACs can be reused by convenient phase separation without obvious diminution of catalytic activity.It is concluded that these PGTACs are potential alternative candidates for esterification reaction in the process of industrial catalysis.

Efficient conversion of H_(2)S into mercaptan alcohol by tertiary-amine functionalized ionic liquids

The resource utilization of hydrogen sulfide(H_(2)S)is of great significance in natural gas chemical industry.Described herein have developed a novel method mediated in tertiary amine-functionalized ionic liquids(ILs)to convert H_(2)S into mercaptan alcohols with enols.The effect of ILs,substra te scope,and regeneration experiments have been investigated.It is found that the conversion of 3-methyl-2-buten-1-ol by H_(2)S can reach 52%with a 50%(mol)catalyst loading of bis(2-dimethylaminoethyl)ether methoxyacetate within 12 hat 90℃.The reaction mechanism was speculated based on theoretical calculation.Besides,a plausible reaction-separation-integrated strategy was further proposed.This work reveals an effective insight into the capture and catalytic conversion of H_(2)S to high valuable mercaptan alcohol,which makes the utilization method of H_(2)S resource universal and has the potentiality for industrial application.

Facilitated transport separation of CO_(2) and H_(2)S by supported liquid membrane based on task-specific protic ionic liquids

Selective separation of CO_(2) and H_(2)S from CH_(4) is of importance to the natural gas upgrading because of its cor-rosivity. As is well known, amine group can recognize reversibly CO_(2) and H_(2)S with a moderate interaction. Withthis in mind, this work prepared a series of amine-functionalized supported-protic-ionic-liquid membranes(SPILMs) for the selective separation of CO_(2) and H_(2)S from CH_(4) . For comparison, aprotic ionic liquid membranewas also prepared for natural gas sweetening. The effect of temperature and transmembrane pressure differenceon the permeability of single gas and ideal selectivity of CO_(2)/CH_(4) and H_(2)S/CO_(2) were studied. Facilitated transportmechanism was studied by NMR spectra. The permeability of CO_(2) in primary amine functionalized [DMPDAH][Tf_(2)N]-based membrane decreases with the increasing transmembrane pressure, indicating a typical feature offacilitated transport membrane. The permeability of CO_(2) and the ideal selective of CO_(2)/CH_(4) are as high as 2000 barrers and 53.2 at 313.2 K in [DMPDAH][Tf_(2)N] membrane, significantly higher than those in conventional ILsmembrane. It is anticipated that these amine-functionalized SPILMs can provide alternative insight for the se-lective separation of CO_(2) and H_(2)S from CH_(4) .