เอกสารการประชุมวิชาการและเสนอผลงานวิจัย มหาวิทยาลัยทักษิณ ครั้งที่ 19 2552 - page 35

„µ¦ž¦³»¤ª·µ„µ¦Â¨³Áœ°Ÿ¨Šµœª·‹´¥ ¤®µª·š¥µ¨´¥š´„¬·– ‡¦´ÊŠš¸É 19 ž¦³‹Îµže 2552
„µ¦Á„·—°´œ˜¦„·¦·¥µ °Š¢°Á¢˜œÃ‡¦Š¦o µŠŽ¸Ã°Å¨˜rœ·— H-ZSM-5
The interaction of phosphate on the ZSM-5 Zeolite
¥³Ã„p³ µÁ¦È¤—µÁ³1* ¨³°»¬µ °oœš°Š2
Yakoh Kharemdabeh1* and Usa Onthong2
š‡´—¥n°
„µ¦Á„·—°´ œ˜¦„·¦·¥µ °Š¢°Á¢˜œÃ‡¦Š¦oµŠŽ¸Ã°Å¨˜rœ· — H-ZSM-5 —oª¥¦³Á¸¥ª· ›¸„µ¦‡Îµœª–
ONIOM2(B3LYP/ 6-31G(d,p):UFF) ¡ªnµ extended structure °ŠŽ¸Ã°Å¨˜r¤¸Ÿ¨˜n °Ã‡¦Š¦oµŠÂ¨³„µ¦Á„·—
°´œ˜¦„·¦·¥µ °Š¦³: H3PO4/H-ZSM-5 Ž¸Ã°Å¨˜r ¤¸ ‡nµ¡¨´ŠŠµœ„µ¦—¼—Ž´ (adsorption energy) Ášnµ„´ -26.23
kcal/mol 宦´Â‹Î µ¨°Š 5T-quantum cluster ¨³ 12T, 34T, 128T ONIOM2 model (T= tetrahedron) ¤¸ ‡nµ
¡¨´ŠŠµœ„µ¦—¼ —Ž´ (adsorption energy) Ášn µ„´ -28.76, -37.34 ¨³ -39.47 kcal/mol ˜µ¤¨Î µ—´ ‹µ„Ÿ¨„µ¦«¹ „¬µœ¸Ê
—ŠÄ®oÁ®Èœªnµ¤´˜·„µ¦—¼ —Ž´ °Š¢°Á¢˜œŽ¸Ã°Å¨˜rœ· — H-ZSM-5 ¹Êœ°¥¼n„´Ã‡¦Š¦oµŠš¸É‹Î µÁ¡µ³Á‹µ³‹Š
°ŠŽ¸Ã°Å¨˜r
‡ÎµÎµ‡´ : Ž¸ ðŨ˜rœ·— H-ZSM-5 ¢°Á¢˜ „µ¦—¼—Ž´
Abstract
An ONIOM (Our-own-N-layered Integrated molecular Orbital + molecular Mechanics) method has
been employed to investigate the interactions between adsorbed H3PO4 on the active hydrogen center in
H-ZSM-5. The adsorption energy of H3PO4 on H-ZSM-5 calculated by the 5T quantum cluster is only -26.23
kcal/mol, whereas, the 12T, 34T, 128T ONIOM model gives the adsorption energy of -28.76, -37.34 and
-39.47 kcal/mol, respectively. The results demonstrate that the adsorption properties of phosphate compounds
on the H-ZSM-5 depend on the specific environment of zeolite.
Keywords: H-ZSM-5 Zeolite; Phosphate; Adsorption; ONIOM
1 œ· ·˜´–”·˜«¹„¬µ £µ‡ª· µÁ‡¤¸ ‡–³ª·š¥µ«µ˜¦r ¤®µª·š¥µ¨´¥š´„¬·– Š ¨µ 90000
2 Ÿ¼o nª¥«µ˜¦µ‹µ¦¥r —¦. £µ‡ª·µÁ‡¤¸ ‡–³ª·š¥µ«µ˜¦r ¤®µª· š¥µ¨´¥š´„¬·– Š ¨µ 90000
* Corresponding author: Ú¦«´¡šr/Ú¦µ¦: 0-7444-3966 Email-usa@tsu.ac.th