CAJ | 학술논문

以白炭黑为硅源、硼酸为硼源、NaOH为碱源、四丙基溴化铵（ TPABr）和1，6-己二胺（ HM DA）混合模板剂，采用水热合成法制备含硼杂原子Na-B-ZSM-5分子筛，用XRD、SEM、FT-IR、UV-vis、11 BM AS NMR、NH3-TPD等方法对其进行表征。在连续流动常压固定床反应器上评价Na-B-ZSM-5分子筛对甲醇脱氢制甲醛反应的催化性能，考察n（ Si）/n（ B）、n（ Na2 O）/n（ SiO 2）、晶化温度和晶化时间等制备参数以及反应温度和质量空速等工艺参数对催化性能的影响。结果表明，硼进入了分子筛的骨架结构中，存在与B酸中心有关的骨架四配位硼和与L酸中心有关的骨架三配位硼，Na-B-ZSM-5分子筛含有较多的弱酸位和少量的中强酸位。催化剂的最佳制备参数为n（ Si）/n（ B）比值为7．5、n（ Na2 O）/n（ SiO2）比值为0．14、晶化温度170℃、晶化时间48 h。 Na-B-ZSM-5（7．5）分子筛在反应温度550℃、质量空速1．85 h-1的反应条件下对甲醇的转化率为62．97％，甲醛的选择性为68．86％。
이백탄흑위규원、붕산위붕원、NaOH위감원、사병기추화안（ TPABr）화1，6-기이알（ HM DA）혼합모판제，채용수열합성법제비함붕잡원자Na-B-ZSM-5분자사，용XRD、SEM、FT-IR、UV-vis、11 BM AS NMR、NH3-TPD등방법대기진행표정。재련속류동상압고정상반응기상평개Na-B-ZSM-5분자사대갑순탈경제갑철반응적최화성능，고찰n（ Si）/n（ B）、n（ Na2 O）/n（ SiO 2）、정화온도화정화시간등제비삼수이급반응온도화질량공속등공예삼수대최화성능적영향。결과표명，붕진입료분자사적골가결구중，존재여B산중심유관적골가사배위붕화여L산중심유관적골가삼배위붕，Na-B-ZSM-5분자사함유교다적약산위화소량적중강산위。최화제적최가제비삼수위n（ Si）/n（ B）비치위7．5、n（ Na2 O）/n（ SiO2）비치위0．14、정화온도170℃、정화시간48 h。 Na-B-ZSM-5（7．5）분자사재반응온도550℃、질량공속1．85 h-1적반응조건하대갑순적전화솔위62．97％，갑철적선택성위68．86％。
Na-B-ZSM-5 molecular sieves were synthesized by hydrothermal method with silica white as silicon source, boric acid as boron source, sodium hydroxide as alkali, and tetrarp opylammonium bromide ( TPABr) and 1,6-hexamethylenediamine ( HMDA) as the hybrid template.The synthesized Na-B-ZSM-5 samples were characterized by XRD, SEM, FT-IR, UV-vis, 11 B MAS NMR and NH3-TPD.Their catalytic performance in methanol dehydrogenation to formaldehyde was evaluated in a fixed-bed reactor under atmospheric pressure and the effects of the catalyst preparation parameters like Si/B molar ratio, basicity, crystallization temperatuer and crystla lization time sa well as the reaction conditions like temperature and space velocity ( WHSV ) on the methanol dehydrogenation behavior were investgi ated.The results indicated tah t boron atoms are introduced into the framewokr of Na-B-ZSM-5m oleuc lar sieves, present as the Bronsted acid siet s from four-coordinated bor on atoms and Lewis acid sites from tricoor dinta ed boron aot ms.Na-B-ZSM-5 molecular sieve s contia n moer weak acid sites and less middle-strong acid sites.The optimized preparation parameters of the Na-B-ZSM-5 molecular sieve are as follows: 7.5 of Si/B molar ratio, 0.14 of Na2 O/SiO2 molar ratio, 170 ℃ of crystallization temperature and 48 h of crystallization time.The conversion of methanol and the selectivity to formaldehyde reach 62.97%and 68.86%, respectively, under the reaction conditions of 550℃and a WHSV of 1.85 h-1 over the optimized Na-B-ZSM-5 molecular sieve.