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.

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) .

Sensitivity of Estimated Total Canopy SIF Emission to Remotely Sensed LAI and BRDF Products

Remote sensing of solar-induced chlorophyll fluorescence(SIF)provides new possibilities to estimate terrestrial gross primary production(GPP).To mitigate the angular and canopy structural effects on original SIF observed by sensors(SIF_(obs)),it is recommended to derive total canopy SIF _(emission)(SIF_(total))of leaves within a canopy using canopy interception(i0)and reflectance of vegetation(R_(V)).However,the effects of the uncertainties in i_(0) and R_(V) on the estimation of SIFtotal have not been well understood.Here,we evaluated such effects on the estimation of GPP using the Soil-Canopy-Observation of Photosynthesis and the Energy balance(SCOPE)model.The SCOPE simulations showed that the R^(2) between GPP and SIF_(total) was clearly higher than that between GPP and SIFobs and the differences in R^(2)(ΔR^(2))tend to decrease with the increasing levels of uncertainties in i_(0) and RV.The resultantΔR^(2) decreased to zero when the uncertainty level in i0 and RV was~30%for red band SIF(RSIF,683 nm)and~20%for far-red band SIF(FRSIF,740 nm).In addition,as compared to the TROPOspheric Monitoring Instrument(TROPOMI)SIFobs at both red and far-red bands,SIF_(total) derived using any combination of i_(0)(from MCD15,VNP15,and CGLS LAI products)and RV(from MCD34,MCD19,and VNP43 BRDF products)showed comparable improvements in estimating GPP.With this study,we suggest a way to advance our understanding in the estimation of a more physiological relevant SIF datasets(SIF_(total))using current satellite products.