US 8,993,793  Bl  12  11  Example 4  Catalytic Esterification Reactions  The reactions were carried out using an equal amount of  catalytic sites in a capped tubular reactor. For example, the  reaction mixture consisting ofheptanoic acid ( 49.8 mg, 0.383  mmol), benzyl alcohol ( 41.4 mg, 0.383 mmol) and catalysts  (0.2 mo!%) in 1 ml ofheptanes was heated at 60°  C. for 1.5  h. The catalysts were isolated by centrifuge and washed with  10 ml of heptane.  Diphenyl ether ( ca. 100 mg), was added into the combined  heptane solution as an internal standard. The reaction conver› sion and product yield were determined by gas chromatogra› phy using a HP-5 colunm. The oven temperature was initially  set at 40°  C. for 4 min, then increased to 250°  C. with a ramp  rate of 10°  C./min, and kept at 250°  C. for 5 min.  The peaks corresponding to all reagents and products were  separated, and their integrated intensities were calibrated  using an internal standard. For the recyclability test, the reac› tion mixture of 3-phenylpropanoic acid (57.5 mg. 0.383  mmol), benzyl alcohol ( 41.4 mg, 0.383 mmol), and 0.4 mo!%  of Cat Bin 1 ml of heptane was stirred at 70°  C. for 2.5 h. The  filtered catalyst was dried under vacuum for 24 h and  recharged with the same amount of starting material for each  run.  REFERENCES  The documents listed below are incorporated by reference  herein as though fully set forth.  [1] M. Bender,  Bio resource Technol.,  70, 80 (1999); M Diasa› kou et al.,  Fuel,  77, 1297 (1998); T. Ogoshi etal.,J.  Am. Oil  Chem. Soc.,  62, 331 (1985)  [2] G. J. Suppes et al.,  J. Am. Oil Chem. Soc.,  78,839 (2001);  G. Kildrian et al., op. cit., 73, 225 (1996); J. Encinar et al.,  Ind. Eng. Chem. Res.,  38, 2927 (1999).  [3] F. Ma et al.,  Ind. Eng. Chem.,  37, 3768 (1998).  [ 4] D. G. B. Boocock et al.,  J. Am. Oil Chem. Soc.,  75, 1167  (1998).  [5] H. N. Basu et al. (U.S. Pat. No. 5,525,126).  [6] S. 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While in  the foregoing specification this invention has been described  in relation to certain preferred embodiments thereof, and  many details have been set forth for purposes of illustration it  will be apparent to those skilled in the art that the invention is  susceptible to additional embodiments and that certain of the  details described herein may be varied considerably without  departing from the basic principles of the invention.  What is claimed is:  1.  A method for preparing an ester, comprising combining  an organic acid, an alcohol, and an acidic mesoporous silicate  under conditions wherein the mesoporous silicate catalyzes  the formation of the ester of the acid and the alcohol and  wherein the silicate comprises diarylammonium triflate  groups and perfluoroaryl groups in the pores of said silicate,  wherein said groups are linked to the silicate matrix by inert  organic groups.  2.  A method for preparing a fatty acid (C$_{1 }$-C$_{3}$ )  alkyl ester  from a fatty acid comprising combining a fatty acid, a (C$_{1 }$-C$_{3}$ )  alcohol, and an acidic mesoporous silicate under conditions  wherein the mesoporous silicate catalyzes formation of the  corresponding (C$_{1 }$-C$_{3}$ )  alkyl ester, and wherein the silicate  comprises diarylammonium triflate groups and perfluoroaryl  groups in the pores thereof, wherein said groups are linked to  the silicate matrix by inert organic groups.  3.  A method for preparing fatty acid (C$_{1 }$-C$_{3}$ )  alkyl esters  from a feedstock comprising one or more fatty acid glycerol  esters and one or more fatty acids comprising combining the  feedstock, a (C$_{1}$-C$_{3}$ ) alcohol, and an acidic mesoporous sili› cate under conditions wherein the mesoporous silicate cata› lyzes the formation of the corresponding fatty acid (C$_{1 }$-C$_{3}$ )  a)kyl es!ers, and wherein the silicate comprises diarylammo› mum tnflate groups and perfluoroaryl groups in the pores  thereof, wherein said groups are linked to the silicate matrix  by inert organic groups.  4.  The method of claim  1, 2 or 3  wherein the said diary› lammonium triflate groups comprise 2,4,6-trimethylphenyl  (phenyl) ammonium triflate moieties.  5.  The method of claim  1, 2 or 3  wherein the perfluoroaryl  groups are pentafluorophenyl groups.  6.  The method of claim  1, 2 or 3  wherein the acidic meso› porous silicate is in the form of particles having a diameter of  about 100-500 nm.  7.  The method of claim  1, 2 or 3  wherein the pores have a  diameter of about 1-5 nm. 