燃料化学学报
燃料化學學報
연료화학학보
JOURNAL OF FUEL CHEMISTRY AND TECHNOLOGY
2008年
6期
772-776
,共5页
冯利利%齐兴义%李俊英%朱岳麟%朱立群
馮利利%齊興義%李俊英%硃嶽麟%硃立群
풍리리%제흥의%리준영%주악린%주립군
锌%AFI结构%正己烷%催化裂解%单分子反应机制
鋅%AFI結構%正己烷%催化裂解%單分子反應機製
자%AFI결구%정기완%최화렬해%단분자반응궤제
zinc%AFI topology%n-hexane%catalytic cracking%monomolecular protolytic mechanism
采用静态水热法合成了含有不同锌含量的锌铝磷酸盐分子筛(ZnAPO-5), 利用XRD、SEM、N2-吸附、MAS-NMR及ICP-AES等方法对合成的ZnAPO-5分子筛进行了表征.研究结果表明在选定的合成条件下, 可以合成出AFI结构类型的ZnAPO-5分子筛, 合成的ZnAPO-5分子筛结晶度较高, 具有规整的六方棱柱晶体外形, 杂原子同晶取代为锌取代骨架元素铝.ZnAPO-5分子筛上的正己烷催化裂解反应活性评价结果显示在反应温度为723K~823K时正己烷的催化裂解呈中等反应活性, 正己烷的转化率随反应温度和接触时间的增加而增加, 正己烷的浓度项反应级数为1, 裂解反应表观速率常数随反应温度的升高而增大, 且遵从Arrhenius公式; 由裂解产物分布可知, 在选定的实验条件下该反应以单分子反应为主.
採用靜態水熱法閤成瞭含有不同鋅含量的鋅鋁燐痠鹽分子篩(ZnAPO-5), 利用XRD、SEM、N2-吸附、MAS-NMR及ICP-AES等方法對閤成的ZnAPO-5分子篩進行瞭錶徵.研究結果錶明在選定的閤成條件下, 可以閤成齣AFI結構類型的ZnAPO-5分子篩, 閤成的ZnAPO-5分子篩結晶度較高, 具有規整的六方稜柱晶體外形, 雜原子同晶取代為鋅取代骨架元素鋁.ZnAPO-5分子篩上的正己烷催化裂解反應活性評價結果顯示在反應溫度為723K~823K時正己烷的催化裂解呈中等反應活性, 正己烷的轉化率隨反應溫度和接觸時間的增加而增加, 正己烷的濃度項反應級數為1, 裂解反應錶觀速率常數隨反應溫度的升高而增大, 且遵從Arrhenius公式; 由裂解產物分佈可知, 在選定的實驗條件下該反應以單分子反應為主.
채용정태수열법합성료함유불동자함량적자려린산염분자사(ZnAPO-5), 이용XRD、SEM、N2-흡부、MAS-NMR급ICP-AES등방법대합성적ZnAPO-5분자사진행료표정.연구결과표명재선정적합성조건하, 가이합성출AFI결구류형적ZnAPO-5분자사, 합성적ZnAPO-5분자사결정도교고, 구유규정적륙방릉주정체외형, 잡원자동정취대위자취대골가원소려.ZnAPO-5분자사상적정기완최화렬해반응활성평개결과현시재반응온도위723K~823K시정기완적최화렬해정중등반응활성, 정기완적전화솔수반응온도화접촉시간적증가이증가, 정기완적농도항반응급수위1, 렬해반응표관속솔상수수반응온도적승고이증대, 차준종Arrhenius공식; 유렬해산물분포가지, 재선정적실험조건하해반응이단분자반응위주.
Zinc-substituted aluminophosphate molecular sieves (ZnAPO-5, AFI topology) containing different zinc contents were synthesized by static hydrothermal method, using triethylamine as an organic template agent. The as-synthesized ZnAPO-5 molecular sieves were characterized by XRD, SEM, N2-adsorption, MAS-NMR and ICP-AES techniques. Experimental data indicate that Zn as a heteroatom was successfully incorporated into the framework of AlPO4-5. The resultant ZnAPO-5 molecular sieves with regular hexagonal prism morphology are of high crystallinity and purity. The n-hexane cracking over ZnAPO-5 was examined under different reaction conditions. It is found that ZnAPO-5 molecular sieves exhibit a moderate activity for the n-hexane cracking conversion in the temperature range of 723K~823K. The cracking results obtained show that the conversion level of n-hexane increased with increasing reaction temperature and contact time, and that the first order was determined in the n-hexane concentration. Relations between rates and reaction temperature can be expressed in terms of Arrhenius formula in the whole temperature range. Based on the kinetic data and product distributions, monomolecular protolytic mechanism was concluded to prevail under the reaction conditions applied.