本研究延續於弱酸下合成矽酸中孔徑分子篩SBA-15([Si]-SBA-15)基礎來進行直接合成矽酸鋁中孔徑分子篩SBA-15([Si, Al]-SBA-15)的最佳化研究及催化應用。 在直接合成鈉型酸鋁中孔徑分子篩部分,我們利用NaOH來調整溶液的pH值,不論在室溫反應或是經過90℃熱處理後的產物其可合成出矽酸鋁中孔徑分子篩的最佳條件為Al(NO3)3 / NaOH = 1:1.25。所合成出的產物其表面積為800 m2 / g,孔洞大小為60Å。催化活性可接近100%,並且擁有相當豐富的型態變化。 在直接合成酸性酸鋁中孔徑分子篩部分,我們添加有機鹼TMAOH來調整溶液的pH值,不論在室溫反應或是經過90℃熱處理後的產物其可合成出矽酸鋁中孔徑分子篩的最佳條件為Al(NO3)3 / TMAOH = 1:1.0。所合成出的產物其表面積為700 m2 / g,孔洞大小為70Å。催化活性也可接近100%,並且擁有相當豐富的型態變化。 若是將硝酸鋁與異丙氧基鋁混合所合成出的矽酸鋁中孔徑分子篩,其最佳合成條件為硝酸鋁/異丙氧基鋁為1:3,我們可以合成出相當接近理論值的Si / Al比值,且其表面積為700 m2 / g,孔洞大小為70Å並具有相當高的催化活性(>90%)。雖然無豐富的型態變化但其產物的顆粒大小會隨異丙氧基鋁的含量增加而變小;反之,會隨增加硝酸鋁的含量而變大。
Aluminium-incorporated mesoporous molecular sieves SBA-15 have been obtained by direct synthesis at low acid concentration and at room temperature for 72 h and 90℃ for 24 h. The condition of preparing Na+- [Si, Al]-SBA-15 is Al(NO3)3:NaOH =1:1.25. The resulting materials retain the hexagonal order and physical properties of pure siliceous SBA-15. It shows a very narrow pore size distribution with an average mesopore size of 60Å and a high surface area of 800 m2 / g. The condition of preparing H+- [Si, Al]-SBA-15 is Al(NO3)3:TMAOH = 1:1.0. It also shows narrow pore size distribution with an average mesopore size of 70Å and a high surface area of 700 m2/ g .The morphology of Na+-[Si, Al]-SBA-15 or H+-[Si,Al]-SBA-15 controlled by acid concentration shows a variety of morphology such as rod, U-shape, hexagon, donut, ball and coral. The catalytic activity of the prepared [Si,Al]-SBA-15 was evaluated by using the cumene cracking reaction and was much higher than that of MCM-41 analog. The condition of preparing high order [Si,Al]-SBA-15 is Al(NO3)3:Al(OCH(CH3)2)3 = 1:3. The resulting materials retain the hexagonal order and physical properties of pure siliceous SBA-15 and it can find that major part of aluminum in [Si,Al]-SBA-15 can be easily incorporated into framework of SBA-15 without structure deformation. It shows narrow pore size distribution with an average mesopore size of 70Å and a high surface area of 700 m2/ g .
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