PHAN Q N G OXI H O A a-PINEN TREN HE XUC TAG DA OXIT V2O5-ZRO2/MCM-4I OXIDATION OF aPINEN OVER OXIDE SYSTEM V2O5-ZRO2/MCM-4I IRAN THI NHLTMAI, NGUYEN THI HA, NGUYEN THI MINH THU, Khoa Hod - DH KHTN-DHQG Ha Ngi NGO QUOC TUAN Tong Cong ty Hoa ddu Viet Nam Abstract V20s-Zr02/MCM-41 catalyst has been prepared, characterzied by by IR, XRD, N2 adsorption, HPTEM, TPR and applied as a bifimctional catalyst to oxidation of a-pinene via a-pinene oxide using O2IH2O2 as an oxidant Besides main epoxide products, the reaction leads to formation of ally lie oxidation products like verbenol and verbenon To suppress the formation of byproducts, the control of effects of temperature, time, solvent is essential for conversion of apinene to a-pinene oxide Gidi thieu a-pinen, la loai hgp chat cd nhieu tu nhien Su oxi hda a-pinen dugc quan tarn Idn bdi cac san pham ciia nd cd nhieu ling dung quan trgng, vi du nhu verbenon, diing de tong hgp taxol, la mot tac nhan dugc ly Con cac san ph^m tecpenic andehyt, rugu, este va epoxi dugc xem nhu cac cha't dau lam dugc pham, tao nude hoa, cha't tao huong Dac biet la cac chat epoxi dugc diing rdng rai nhu la 997 cac nguyen lieu thd cho cac loai nhua epoxi, sou, uao L/iyi n* ^ „i xv.«i dgng be mat, lam chat phu gia chdng oxi hoa hoac phu gia cue ap va cac chat trung gian tong hgp hiru ca tinh khiet [1,2,3,4] Trong hda hoc tecpen, su epoxi hoa chgn Igc la ra't quan trgng Cac chat oxi hoa theo ti le hgp thiic dung cho phan ling thudng la cac peaxit hiru ca, phuang phap tao nhieu san pham phe thai, han nira khdng chgn Igc vdi cac epoxi nhay axit Tranh hien tugng nay, nhieu nghien ciiu che tao he xuc tac khac nhu cac hgp chat ciia vonfram, xiic tac nhdm silicat mang titan, peroxovonframphotphat, molypden, phiic vanadi, mangan, da dugc sir dung cho nhieu mii"c cdng cung nhu la han che khac Nghien cu:u tim hieu kha nang oxi hoa chgn Igc tao cac san pham oxi hoa rieng biet apinen la va'n de it dugc thuc hien d Viet Nam Trong cdng nghe che tao phu gia, chat boat dgng be mat, nhi6u tac gia mudn thuc hien qua trinh epoxi hoa hoac hidroxi hda cac hgp chat chiia nd'i ddi tao cac san pham cd gia tri ling dung mdi Qua trinh oxi hoa olefin tren cac he xiic tac khac dang thu hiit nhieu tac gia tren the gidi quan tarn [2,6] san pham da dang, phirc tap, vi vay viec tim dugc he xdc tac cd hieu qua, chgn Igc la di6u can thie't He vat lieu da kim loai oxit vdi nhieu hieu irng va nhiing tinh nang xiic tac mdi hien dang dugc chii y Vanadi oxit dugc quan tam che tao to hcfp vdi cac oxit kim loai khac de tao xiic tac vdi cac hieu ling mdi Trong nghien ciiu thuc hien che tao he xiic tac V205-Zr02/MCM-41, nghien ciiu dac trung vat ly tinh chat xiic tac da oxit va mdi quan he giira ca'u true va tinh chat ciia qua trinh oxi hoa a-pinen nham tim nhiing di6u kifen chgn Igc cho san pham a-pinenoxit Thi/c nghiem Mau MCM-41 dugc tong hgp tii tetraetylorthosilicat Si(OC2H5)4va chat hoat dgng be mat BRIF-56 la xetylpolietilenoxit C,6H33(OC2H4),oOH: Chat hoat dgng be mat khdng ion xetylpolietilenoxit BRIJ-56 dugc hoa tan lugng nude cat vira dii Sau dd dugc them vao lugng amoniac du de tao mdi trudng kiem (pH~9) Dung dich nguon Silic dung de tong hgp (thuy tinh long, tetraorthosilicat TEOS ) dugc nho 998 tut tii v^o dung dich cha't hoat ddng be mat cr trSn, ddng thdi khua'y manh gid K6't qua thu dugc gel mau trang due, Igc san ph^m thu dugc bang cdn dS'n mdi trudng pH~7 Sa'y khd san phdm qua dem d 90''C va sau dd nung d 550°C gid de loai cha't tao ca'u triic thu dugc bgt min, xd'p Tien hanh dua oxit ciia vanadi va zirconi len vat lieu MCM-41 da tong hgp dugc Ham lugng phiic ciia vanadi (vanadioxalat) hoac amonivanadat dugc tinh toan dii de che tao he 10%V2O5 10%Zro2/MCM-41 dugc tam vao lugng 10% Zr02 tren MCM-41 da di^u ch6' d tren, de yen 24 gid d nhiet phdng, sa'y khd d 120"C gid va hoat hoa d 450''C gid Xiic tac sau dugc xir ly hai nude dugc nghien ciiu trang thai phan tan ciia cac oxit tren MCM-41 bang phuang phap khir H2 theo chuang trinh nhiet do; nhilu xa tia X viing gdc hep, hong ngoai, ha'p phu nita tren may ASAP 2010 (Micromeritics Autochem II-USA) d nhiet 77 K; hien vi dien tir truyen qua phan giai cao dugc chup tren may JEM 1010 d hieu dien the 80-110 KV Phuang phap khir hoa theo chuang trinh nhiet dugc diing de nghien ciiu trang thai oxy hoa khir ciia be mat va khdi chat ran Qua trinh khir hoa dugc tien hanh tren may AutoChem II 2920 Micromeritics Phan ling epoxi hoa a-pinen tren xiic tac 10%V2O5-ZrO2/MCM-41 dugc thuc hien pha long Ket qua phan ling dugc phan tich tren he may GCMS, HP 6890 Ket qua va thao luan MCM-41 thudc ho vat lieu mao quan trung binh MS-41S cd cau triic luc lang Vat lieu MCM-41 cd dudng cong ha'p phu-giai hap N2 ma theo su phan loai ciia lUPAC la dang dudng dang nhiet ha'p phukhir ha'p phu ling vdi VLMQ Dudng cong cd vdng tre la dudng cong dac trung cho VLMQTB cd kich thudc mao quan tiir 20-500A Dudng phan bd kfch thudc mao quan ciia miu cho ta thay dudng kinh O mao quan trung binh ban dau la 38A, sau dua cac oxit kim loai len O giam cdn 30A Viec mang cac oxit len MCM-41 dugc nghien ciiu bang phuang phap khir hoa H2 theo chuang trinh nhiet Phuang 999 khdi chat rdn Ket qua tren gian dd kuu mcu i.-uuvjiig im.n imxy, ^y ,.,«« mau 10%V2O5-ZrO2/MCM-41, cho thay hai pic d nhiet thap han la 510"C va pic d 430"C tuang irng vdi qua trinh khir V5+ — - V4+ va V4+ — - V3+, va phan anh su ciing ton tai ciia hai dang monovanadat biet lap (VOJ va polyvanadat ([VOJ)[2,3] Difeu cho tha'y: Khi ham lugng vanadioxit phan tan thap vao mao quan MCM-41 cd kha nang dat trang thai dan lap va ton tai d dang monovanadat biet lap (VO^) va polyvanadat ([VOJ) Chinh sir phan tan deu tren be mat Zr02 -SiO nen nd d6 bi khir, la hai dang ton tai ciia vanadioxit c6 kha nang lam xiic tac tot va cd tinh chat rieng biet cho qua trinh oxi hoa Tren gian dd khdng thay xuat hien pic khir dac trung cho ZrOz, chiing to viing nhiet nghien ciiu, ZrOjChua bi khir 700 •I \ -000s