เอกสารการประชุมวิชาการและเสนอผลงานวิจัย มหาวิทยาลัยทักษิณ ครั้งที่ 19 2552 - page 40

„µ¦ž¦³»¤ª·µ„µ¦Â¨³Áœ°Ÿ¨Šµœª·‹´¥ ¤®µª·š¥µ¨´¥š´„¬·– ‡¦´ÊŠš¸É 19 ž¦³‹Îµže 2552
‹µ„ǦŠ¦oµŠÂ—Š°´œ˜¦„·¦·¥µ °Š¦³ [H3PO4]/[H-ZSM-5], 128T-ONIOM model ¡¨´ ŠŠµœš¸Éŗo
‹µ„„µ¦‡Îµœª–—oª¥¦³Á¸ ¥ª·›¸ ONIOM2(B3LYP/6-31g(d,p):UFF) ¤¸‡nµ¡¨´ŠŠµœ °Š¦³Ášn µ„´ -2330.59 a.u.
¨³¡¨´ŠŠµœ„µ¦—¼—Ž´ (adsorption energy) Ášnµ„´ -39.47 kcal/mol ¦·Áª–š¸ÉÁ„· —ž’·„·¦·¥µ‡º°¦·Áª–°³˜°¤
°°„Ž·Á‹œš¸É 3 „´°³˜°¤ °ŠÅ±Ã—¦Á‹œ (Hz) ¤¸‡ªµ¤¥µª¡´œ›³ O3-Hz Ášnµ„´ 1.46 Š¨³°³˜°¤°°„Ž·Á‹œš¸É 2
„´°³˜°¤Å±Ã—¦Á‹œ (H) ¤¸ ‡ªµ¤¥µª¡´œ›³ O2-H Ášnµ„´ 1.69 Å
˜µ¦µŠš¸É 1 —ŠŸ¨ °Š framework ˜n°¡¨´ŠŠµœ„µ¦—¼—Ž´ ¦³®ªnµŠ H3PO4 „´ H-ZSM-5 zeolite
Method Adsorption energies (kcal/mol)
H3PO4/H-ZSM-5
5T 12T 34T 128T
Full B3LYP/6-31G(d,p) -26.23 - - -
ONIOM(B3LYP/6-31G(d,p):UFF) - -28.77 -34.34 -39.47
˜µ¦µŠš¸É 2 —Š‡ªµ¤¥µª¡´œ›³Â¨³¤» ¤š¸Éŗo‹µ„„µ¦‡Î µœª–Äœ¦³ H3PO4 „´ H-ZSM-5 zeolite
Parameters B3LYP/6-31G(d,p) B3LYP/6- 31G(d,p):UFF
5T 12T 34T 128T
(Å) Isolated Complex Isolated Complex Isolated Complex Isolated Complex
Distances
O1-Hz 0.983 1.050 1.000 1.029 0.969 1.047 1.047 1.047
Al-O1 1.838 1.803 1.799 1.786 1.743 1.765 1.765 1.765
Si1-O1 1.685 1.684 1.693 1.685 1.680 1.662 1.662 1.662
Al-O2 1.720 1.735 1.711 1.710 1.649 1.698 1.698 1.698
Si2-O2 1.635 1.639 1.640 1.631 1.607 1.612 1.612 1.612
O3-Hz 1.829 1.431 1.690 1.528 1.821 1.455 1.455 1.455
O4-H 0.983 1.021 1.010 1.007 0.960 1.003 1.003 1.003
H-O2 1.888 1.550 1.661 1.676 2.247 1.693 1.693 1.693
P-O3 1.477 1.508 1.528 1.496 1.760 1.506 1.506 1.506
P-O4 1.586 1.572 1.567 1.573 1.760 1.582 1.582 1.582
Angles
‘ Si1-O1-Al 130.708 127.674 135.228 133.988 129.636 129.573 129.574 129.574
‘ Si2-O2-Al 131.696 132.461 138.145 139.890 141.189 135.195 135.195 135.195
‘ O1-Al-O2 91.179 94.406 94.554 95.674 94.148 92.951 92.951 92.951
‘ O3-P-O4 113.707 114.049 113.603 115.401 109.471 112.656 112.656 112.656
‘ P-O4-H 109.920 112.336 110.258 109.561 109.500 111.048 111.048 111.048