염산 및 불산처리 모더나이트의 산특성과 촉매활성

한영택; 하백현

Journal of the Korean Industrial and Engineering Chemistry, Vol.2, No.1, 77-85, March, 1991

Export Citation

염산 및 불산처리 모더나이트의 산특성과 촉매활성

Acid Property and Catalytic Activity on Mordenites Treated by Hydrochloric Acid and Hydrofluoric Acid

한영택, 하백현

초록

염산 및 불산으로 모더나이트를 처리하여 실리카/알루미나 비가 다른 일련의 시료를 만들었다. 이러한 시료에 대하여 암모니아 TPD와 피리딘 흡착으로 IR을 이용하여 산성도를 측정하고 o-xylene 반응의 활성과 이성화반응에 대한 선택성을 측정하였다. 그 결과 염산처리 시료는 실리카/알루미나 비가 증가할수록 구조알루미늄이 추출되어 산량이 감소하였으며 실리카/알루미나 비가 22인 시료가 다른 시료들보다 활성이 좋았다. 불산처리 시료는 불산처리 시 불소가 구조중 규소원자와 결합하였으며 처리시간이 증가함에 따라 결합된 불소는 증가하였다. 이 경우의 활성은 염산처리와는 달리 알루미늄의 추출과 함께 모더나이트의 수산기가 불소로 치환되어 이로 인하여 산점이 줄어 활성이 감소하나 불산은 규소도 추출하므로 표면을 파고들어 새로운 면이 노출되어 산점이 형성되고 이 산점은 증가된 결합불소의 영향을 받아 강해지면서 활성이 다소 증가하였다.

A series of samples having different SiO₂/Al₂O₃ ratio were prepared by treating hydrogen mordenites with boiling hydrochloric acid and with hydrofluoric acid. The acidities of these samples were measured by TPD of NH₃ and by pyridine adsorption using IR, and the catalytic activities and selectivities of isomerization were measured for the reaction of ortho-xylene. For the samples treated by boiling hydrochloric acid, the acidities decreased with the increasing SiO₂/A1₂O₃ ratio caused by the extraction of framework aluminum. The sample having the SiO₂/A1₂O₃ ratio or 22 showed better activity than the others. For the samples treated by hydrofluoric acid, the content of chemicallv binding fluorine increased with the increasing contact time of hydrofluoric acid solution. The catalytic activities decreased with the hydrofluoric acid treatment due to the decreased acid sites resulted iron the extrartion of aluminum and silicon as well as the hydroxyl group replacement by the fluoride ion. The slightly increasing catalytic activities, however, came from the newly created acid sites, due to the removal of surface silicon, having enhanced by the inductive effect of binding fluorin with further acid treatment.

[References]

Ha BH, HWAHAK KONGHAK, 12(2), 75 (1974)
Derouane EG, "Catalytic Materials," ACS, Washington D.C., 157 (1984)
Stucky GD, Dwyer FG, "Intrazeolite Chemistry," ACS, Washington D.C., 41 (1983)
Mannes JA, Dooley KM, J. Catal., 117, 322 (1989)
Bosacek V, Schirmer W, Thamm H, J. Catal., 61, 435 (1980)
Meyers BL, Fleisch TH, Hall JB, J. Catal., 110, 82 (1988)
Eberly PE, Kimberlin CN, Ind. Eng. Chem. Prod. Res. Dev., 9(3), 335 (1970)
Olsson RW, Rollmann LD, Inorg. Chem., 16(3), 651 (1977)
Hidalgo CV, J. Catal., 85, 362 (1984)
Ghosh AK, Kydd RA, J. Catal., 103, 399 (1987)
Choudhary VR, Ind. Eng. Chem. Prod. Res. Dev., 16(1), 12 (1977)
Ha BH, Guidot J, Barthomeuf D, J. Chem. Soc.-Faraday Trans., 75, 1245 (1979)
Rabo JA, "Zeolite Chemistry and Catalysis," ACS, Washington, D.C., 118 (1976)
Ratnasamy P, Sivasankar S, Vishnoi S, J. Catal., 69, 428 (1981)
Hansford RC, Ward JW, J. Catal., 13, 316 (1969)
Csicsery SM, Hickson DA, J. Catal., 19, 386 (1970)
Miradatos C, Ha BH, Barthomeuf D, Proc. 5th Int. Conf. on Zeolite, Naple, 383 (1980)

[Referenced By]

[1] Ha BH, HWAHAK KONGHAK, 12(2), 75 (1974)

[2] Derouane EG, "Catalytic Materials," ACS, Washington D.C., 157 (1984)

[3] Stucky GD, Dwyer FG, "Intrazeolite Chemistry," ACS, Washington D.C., 41 (1983)

[4] Mannes JA, Dooley KM, J. Catal., 117, 322 (1989)

[5] Bosacek V, Schirmer W, Thamm H, J. Catal., 61, 435 (1980)

[6] Meyers BL, Fleisch TH, Hall JB, J. Catal., 110, 82 (1988)

[7] Eberly PE, Kimberlin CN, Ind. Eng. Chem. Prod. Res. Dev., 9(3), 335 (1970)

[8] Olsson RW, Rollmann LD, Inorg. Chem., 16(3), 651 (1977)

[9] Hidalgo CV, J. Catal., 85, 362 (1984)

[10] Ghosh AK, Kydd RA, J. Catal., 103, 399 (1987)

[11] Choudhary VR, Ind. Eng. Chem. Prod. Res. Dev., 16(1), 12 (1977)

[12] Ha BH, Guidot J, Barthomeuf D, J. Chem. Soc.-Faraday Trans., 75, 1245 (1979)

[13] Rabo JA, "Zeolite Chemistry and Catalysis," ACS, Washington, D.C., 118 (1976)

[14] Ratnasamy P, Sivasankar S, Vishnoi S, J. Catal., 69, 428 (1981)

[15] Hansford RC, Ward JW, J. Catal., 13, 316 (1969)

[16] Csicsery SM, Hickson DA, J. Catal., 19, 386 (1970)

[17] Miradatos C, Ha BH, Barthomeuf D, Proc. 5th Int. Conf. on Zeolite, Naple, 383 (1980)