본 연구에서는 Dawson형 헤테로폴리산인 H₆P₂W₁₈O₆₂를 제조하여 특성분석을 수행하였으며, 이의 촉매적 특성을 Keggin형 헤테르폴리산 촉매인 H₃PW₁₂O₄₀과 서로 비교하였다. 또한 이들 촉매의 단일 혹은 혼합 촉매계를 TBA와 메탈온로부터 MTBE를 합성하는 기상반응에 적용하였다. 이와 함께 MTBE 합성반응 특성을 이해하기 위해 TBA 탈수반응을 독립적으로 수행하였다. H₃PW₁₂O₄₀는 H₆P₂W₁₈O₆₂보다 강한 산세기를 지니고 있는 것으로 나타났으며, 이 촉매는 TBA 탈수반응에 보다 효율적으로 작용하였다. 또한 Dawson형 촉매는 Keggin 형 촉매보다 MTBE 합성반응에 있어서 더욱 효율적인 촉매로 작용하는 것으로 나타났다. Keggin 및 Dawson형 촉매의 기계적 혼합체는 촉매반응에 있어서 혼합에 따른 상승효과를 보이지 못하였으며, 혼합 촉매계에서 개별 촉매종은 독립적인 촉매 작용을 하는 것으로 나타났다.

A Dawson-type heteropolyacid, H₆P₂W₁₈O₆₂ was successfully prepared and characterized in this work and the catalytic properties of H₆P₂W₁₈O₆₂ were compared with those of Keggin-type heteropolyacid, H₃PW₁₂O₄₀. The single or the mixed catalyst of H₆P₂W₁₈O₆₂ and H₃PW₁₂O₄₀ was applied to the vapor-phase MTBE(methyl tert-butyl ether) synthesis from TBA(tert-butyl alcohol) and methanol. TBA dehydration was independently carried out in order to ensure the reaction characteristics of MTBE synthesis. It was found that H₃PW₁₂O₄₀ retained the higher acid strenght than H₆P₂W₁₈O₆₂ and H₃PW₁₂O₄₀ was more efficient than H₆P₂W₁₈O₆₂in the TBA dehydration. It was also observed that the Dawson-type heteropolyacid was much more efficient than the Keggin-type heterpolyacid in the MTBE synthesis. The mechanical mixture of H₃PW₁₂O₄₀ and H₆P₂W₁₈O₆₂ didn''t show a synergy effect in the catalytic reactions, but only showed the independent catalytic functions of each component itself.

MTBE(Methyl Tert-Butyl Ether) TBA(Tert-Butyl Alcolhol) Methanol 12-Tungstophosphoricacid 18-Tungstophosphoricacid Dawson Heteropolyacid

Misono M, Catal. Rev.-Sci. Eng., 29, 269 (1987)
Kim HC, Moon SH, Lee WY, Chem. Lett., 447 (1991) 
Park GI, Lim SS, Choi JS, Song IK, Lee WY, J. Catal., 178(1), 378 (1998) 
Lee KY, Arai T, Nakata S, Asaoka S, Okuhara T, Misono M, J. Am. Chem. Soc., 114, 2836 (1992) 
Maksimov GM, Kozhevnikov IV, React. Kinet. Catal. Lett., 39, 317 (1989) 
Shikata S, Okuhara T, Misono M, J. Mol. Catal., 100, 49 (1995) 
Shikata S, Nakata S, Okuhara T, Misono M, J. Catal., 166(2), 263 (1997) 
Ito T, Song IK, Inumaru K, Misono M, Chem. Lett., 727 (1997) 
Holscher M, Englert U, Zibrowius B, Holderich WF, Angew. Chem.-Int. Edit. Engl., 33, 2491 (1994)
Comuzzi C, Dolcetti G, Trovarelli A, Cavani F, Trifiro F, Llorca J, Finke RG, Catal. Lett., 36(1-2), 75 (1996) 
Lee WY, Song IK, Lee JK, Park GI, Lim SS, Korean J. Chem. Eng., 14(6), 432 (1997)
Lee JK, Song IK, Park GI, Lee WY, HWAHAK KONGHAK, 35(2), 237 (1997)
Park GI, Lim SS, Choi JS, Song IK, Lee WY, Stud. Surf. Sci. Catal., 118, 477 (1998)
Xin F, Pope MT, Organometallics, 13, 4881 (1994) 
Mansuy D, Bartoli J, Battioni P, Lyon DK, Finke RG, J. Am. Chem. Soc., 113, 7222 (1991) 
Wu H, J. Biol. Chem., 43, 189 (1920)
Comuzzi C, Primavera A, Trovarelli A, Top. Catal., 3, 387 (1996) 
Tsigdinos GA, Hallada CJ, Inorg. Chem., 7, 437 (1968) 
Song IK, Kaba MS, Barteau MA, Lee WY, HWAHAK KONGHAK, 35(3), 407 (1997)
Brown DH, Spectrochim. Acta, 19, 583 (1963)
Okuhara T, Mizuno N, Misono M, Adv. Catal., 41, 113 (1996)
Kaba MS, Song IK, Duncan DC, Hill CL, Barteau MA, Inorg. Chem., 37(3), 398 (1998) 
Kim GJ, Ahn WS, Cho BR, Kwon LM, HWAHAK KONGHAK, 26(5), 526 (1988)
Lee DK, Kim SB, Ahn JH, HWAHAK KONGHAK, 29(1), 49 (1991)
Park JH, Cho HG, Shin JS, Park NC, Kim JS, HWAHAK KONGHAK, 33(1), 19 (1995)
Sugiyama K, Kato K, Miura H, Matsuda T, J. Jpn. Petrol. Inst., 26, 243 (1983)