CN107812518B - 一种高选择性光催化环己烷氧化制备环己烯的方法 - Google Patents
一种高选择性光催化环己烷氧化制备环己烯的方法 Download PDFInfo
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Abstract
本发明涉及一种高选择性光催化环己烷氧化制备环己烯的方法。该方法为:在常温常压下将环己烷与氧气混合,以非化学计量比三氧化钨作光催化剂,在光照下催化环己烷发生脱氢反应生成环己烯,所述的非化学计量比三氧化钨结构式为WO3‑X,WO3‑X中存在氧空位。本发明提供的高选择性光催化环己烷脱氢制备环己烯的方法与传统热催化相比,反应条件更加温和,常温常压下即可发生,具有极高的环己烯产物选择性,选择性几乎为100%,可避免环己烯深度脱氢转化为苯副产物;而且利用氧气为环境友好的氧化剂,整个反应过程无污染,有望在环己烯的合成方面得到广泛应用。由此同时也提供了一种利用太阳光能源的绿色合成新途径。
Description
技术领域
本发明属于催化领域,具体涉及一种高选择性光催化环己烷脱氢制备环己烯的方法。
背景技术
环己烯主要用于有机合成、萃取及溶剂,也可以通过氧化还原反应制备重要的有机合成中间体,广泛应用于医药、食品、农业产品、聚酯和其它精细化工产品的生产。近些年来,在环己烯直接氧化合成己二酸、环己酮、环己醇等方面取得了较大的进展,同时以环己烯为原料生产尼龙6和尼龙66的生产工艺路线,具有较高的经济效益。环己烯被认为是合成环己酮、环己醇、己二酸等的最佳原料,是一种关联度极大的基础化工原料。随着国内尼龙产品的需求量不断增加,其中一半需要进口,在世界上尼龙6、尼龙66的需求量同样很大,但受生产技术的限制,目前国内环己烯的年产量非常低。现有的环己烯生产方法成本高、效率低、污染严重,急需寻求一种环己烯生产的工艺新途径。
环己烯的合成方法主要有:(1)环己醇脱水制备环己烯,工业上一般是以浓硫酸为催化剂,但浓硫酸腐蚀性强,副反应多,会产生大量的废酸水污染环境,不适宜工业生产;(2)苯选择性加氢制备环己烯,苯加氢制环己烯选择性很低,同时会有大量副产物环己烷产生,反应过程中采用贵金属作为催化剂生产成本高,而且生产过程中采用高压对设备要求较高,存在安全隐患;(3)环己烷脱氢制环己烯,环己烷是石油工业的产物,由于其材料价廉易得,可使低价值的环烷烃转化成高附加值的不饱和烃,实现工业生产的实用价值。
相比之下,第三种方法更为经济和可行。但是传统的热催化反应体系主要存在以下难点:(1)传统的热催化反应的温度较高,通常在450~600℃左右,导致环己烯容易发生进一步脱氢而生成苯;(2)如果采用氧分子作为反应物而参与脱氢反应,就存在氧活化后进攻环己烷而生成环己酮、环己醇和CO2等氧化副产物,导致环己烯的选择性不够理想。所以目前环己烷脱氢制备环己烯的关键是选择合适的催化反应体系及催化剂。
相比于传统热催化体系,光催化反应可在常温常压下进行,反应条件温和,因而引起了研究者的兴趣。近年来,光催化反应被应用于有机物的光化学反应,例如福建物构所研究者利用银修饰纳米氧化锌光催化氧化甲烷(Nature Communications,2016,7:12273)。关于光催化环己烷脱氢的研究也有一些报道,有研究者利用五氧化二钒催化剂光催化氧化环己烷(Green Chemistry,2017,19,311-318),但是反应产物大多为环己酮及环己醇等。
至目前为止,尚未见有文献报道提及在光催化条件下将环己烷高选择性转化为环己烯。因此,如能开发一种能高选择性光催化环己烷脱氢至环己烯的方法,对于有机化工而言意义重大,将具有很好的工业化前景。
发明内容
本发明旨在克服现有技术中存在的不足,提供一种高选择性光催化环己烷脱氢制备环己烯的方法,为环己烯的合成提供了一种新途径,该合成方法条件温和,常温常压即可反应,选择性高。
为了实现上述目的,本发明采用的技术方案如下:
提供一种非化学计量比三氧化钨,其结构式为WO3-X,WO3-X中存在氧空位。
按上述方案,所述的非化学计量比三氧化钨WO3-X是将WO3进行紫外处理得到,所述紫外照射波长为300~360纳米,功率为50~100W。
按上述方案,所述的紫外照射处理时间1~2h,紫外灯照射处理至颜色由淡黄色变成深蓝色。
按上述方案,所述的WO3可采用商业WO3;或为采用以下方法自制得到的WO3纳米线:配置钨酸钠水溶液,调节体系的pH至1~2,继续搅拌直到淡黄色沉淀不再产生,随后加硫酸钾(K2SO4),继续搅拌得到乳白色溶液,然后将上述乳白色溶液转移至内衬聚四氟乙烯的不锈钢反应釜中,密封后在170~190℃下反应20~30h,后处理得到WO3纳米线,纳米线的直径为50~80nm。
按上述方案,所述的后处理为将反应后体系自然冷却至室温,离心分离沉淀并用去离子水清洗,并在60℃下干燥即得。
按上述方案,所述钨酸钠和硫酸钾的质量比为2~3:6~10。
提供一种高选择性光催化环己烷脱氢制备环己烯的方法,在常温常压下将环己烷与氧气混合,以非化学计量比三氧化钨作光催化剂,在光照下催化环己烷发生脱氢反应生成环己烯。
按上述方案,所述的环己烷与氧气的混合气的流量按光照面积为1cm2计算,为600~1800mL·h-1·g催化剂 -1。
按上述方案,环己烷与氧气混合的体积比为1:1~2:1。
按上述方案,所述的光照处理为使用氙灯为模拟太阳光源,光照强度为0.4~0.7W·cm-2。
按上述方案,上述高选择性光催化环己烷脱氢制备环己烯的方法,具体步骤为:首先在常温常压下将环己烷与氧气按比例混合,然后将混合气通入装载有光催化剂的石英反应池内,在光照下进行连续流动催化反应,催化环己烷发生脱氢反应生成环己烯,不使用其它辅助加热装置。
环己烯广泛应用于医药和其它精细化工产品的生产,现有的环己烯生产方法成本高及污染严重,迫切需要开发新的工艺途径。通过价廉的环己烷脱氢直接制备环己烯一直是科研和工业领域所追求的目标,但由于传统热催化反应过程中环己烯产物容易发生进一步脱氢而生成苯副产物,同时还存在环己烷的过度氧化而产生环己酮和环己醇,导致环己烯的选择性不够理想。
本发明提供的高选择性光催化环己烷脱氢制备环己烯的方法采用非化学计量比的三氧化钨(WO3-X)作为光催化剂,在光照条件下,三氧化钨半导体材料作用于环己烷使其脱氢而形成环己烯,脱去的氢与表面氧结合后生成水而脱去,由此可实现常温常压温和条件下高选择性合成环己烯,且不会有醇酮类氧化副产物的生成。
本发明的优点是:
1.本发明提供的催化剂三氧化钨为非化学计量比三氧化钨,WO3-X中存在氧空位,具有光吸收能力强、化学稳定性高及合成成本低等优点,易于工业化应用。
2.本发明提供的高选择性光催化环己烷脱氢制备环己烯的方法与传统热催化相比,反应条件更加温和,常温常压下即可发生,具有极高的环己烯产物选择性,选择性几乎为100%,可避免环己烯深度脱氢转化为苯副产物;而且利用氧气为环境友好的氧化剂,整个反应过程无污染,有望在环己烯的合成方面得到广泛应用。由此同时也提供了一种利用太阳光能源的绿色合成新途径。
附图说明
图1为三氧化钨纳米线的扫描电子显微镜图,可以看出纳米线的直径约为50纳米左右。
图2为三氧化钨和非化学计量比三氧化钨的拉曼对比图,非化学计量比三氧化钨(WO3-used)在1521和1127cm-1处出现了新峰,表明其中有氧空位产生。
图3为非化学计量比三氧化钨的电子顺磁共振图,氧空位的特征对称峰非常明显。
图4为三氧化钨和非化学计量比三氧化钨对比X射线光电子能谱图,经过分峰拟合,可以看到非化学计量比三氧化钨样品中存在W5+的特征峰,这更进一步证实有氧空位的存在;
图5为三氧化钨纳米线和非化学计量比三氧化钨的催化活性图;
图6为三氧化钨纳米线光催化条件下产物选择性;
图7为非化学计量比三氧化钨光催化和热催化环己烷结果图。
具体实施方式
实施例1
非化学计量比三氧化钨(WO3-X)的合成:取钨酸钠(Na2WO4·2H2O)2g,溶于50ml去离子水,缓慢搅拌同时滴加稀盐酸溶液调节溶液的pH至1.2,继续搅拌直到淡黄色沉淀不再产生。随后加入6g硫酸钾(K2SO4),继续搅拌1h。将上述乳白色溶液转移至内衬聚四氟乙烯的不锈钢反应釜中,密封后在180℃下反应24h。待自然冷却至室温,离心分离沉淀并用去离子水清洗,并在60℃下干燥,得到化学计量比WO3产物。取上述WO3在100W紫外灯(360纳米波长)照射下处理2h,直至颜色由淡黄色变成深蓝色,得到非化学计量比三氧化钨(WO3-X)。相应的样品表征结果见图1,2,3和4。
图1为三氧化钨纳米线的扫描电子显微镜图,可以看出纳米线的直径约为50纳米左右。
图2为三氧化钨和非化学计量比三氧化钨的拉曼对比图,非化学计量比三氧化钨在1521和1127cm-1处出现了新峰,表明其中有氧空位产生。
图3为非化学计量比三氧化钨的电子顺磁共振图,氧空位的特征对称峰非常明显。
图4为三氧化钨和非化学计量比三氧化钨对比X射线光电子能谱图,经过分峰拟合,可以看到非化学计量比三氧化钨样品中存在W5+的特征峰,这更进一步证实有氧空位的存在;
光催化条件下环己烷的催化转化:
以上述合成的三氧化钨为催化剂,取50mg装入石英反应池进行催化性能评价。在常温常压下首先将环己烷与氧气按2:1比例混合,然后将混合气通过装载有光催化剂的石英反应池,混合气的流量为700mL h-1g催化剂 -1(按光照面积为1cm2计算),光催化过程使用氙灯为模拟太阳光源,光照强度为0.5W cm-2。同时利用气相色谱分析气体产物,图5的结果表明当以化学计量比WO3为催化剂时,环己烷并没有环己烯和其它产物生成。但是当以非化学计量比三氧化钨WO3-X为催化剂时,有环己烯生成且生成速率非常稳定。图6的结果进一步说明气体产物中环己烯的选择性几乎为100%,产物中没有检测到其它副产物(如苯,环己醇或环己酮等)。
纯热条件下环己烷的催化转化(对比实验):以上述合成的非化学计量比三氧化钨WO3-X为催化剂,取50mg装入石英反应池进行催化性能评价。在常温常压下首先将环己烷与氧气按2:1比例混合,然后将混合气通过装载有光催化剂的石英反应池,混合气的流量控制在700mL h-1g催化剂 -1。整个反应过程在避光条件下进行,仅仅利用加热方式控制反应池内的温度。同时利用气相色谱分析气体产物,表1的结果表明在纯热条件下,若反应温度低于200度,WO3-X不能催化环己烷的转化。但是当温度高于200度时,反应产物都是副产物苯,环己烯的选择性几乎为0。这说明在纯热条件WO3-X并不能催化环己烷到环己烯。
表1纯热条件下WO3-x催化环己烷转化的结果
热催化反应温度(℃) | 室温 | 100 | 150 | 200 | 250 |
环己烯产物选择性(%) | 无产物 | 无产物 | 无产物 | 0 | 0 |
苯产物选择性(%) | 无产物 | 无产物 | 无产物 | 100 | 100 |
实施例2
非化学计量比三氧化钨(WO3-X)的合成:取钨酸钠(Na2WO4·2H2O)2g,溶于50ml去离子水,缓慢搅拌同时滴加稀盐酸溶液调节溶液的pH至1.2,继续搅拌直到淡黄色沉淀不再产生。随后加入8g硫酸钾(K2SO4),继续搅拌1h。将上述乳白色溶液转移至内衬聚四氟乙烯的不锈钢反应釜中,密封后在170℃下反应28h。待自然冷却至室温,离心分离沉淀并用去离子水清洗,并在60℃下干燥,得到化学计量比WO3产物。取上述WO3在80W紫外灯(320纳米波长)照射下处理2h,直至颜色由淡黄色变成深蓝色,得到非化学计量比三氧化钨(WO3-X)。
光催化条件下环己烷的催化转化:
以上述合成的三氧化钨为催化剂,取50mg装入石英反应池进行催化性能评价。在常温常压下首先将环己烷与氧气按2:1比例混合,然后将混合气通过装载有光催化剂的石英反应池,混合气的流量为900mL h-1g催化剂 -1(按光照面积为1cm2计算),光催化过程使用氙灯为模拟太阳光源,光照强度为0.7W cm-2。同时利用气相色谱分析气体产物,结果表明环己烯生生成速率为39mmol h-1g-1,环己烯的选择性几乎为100%。
实施例3
取商品化WO3在100W紫外灯(360纳米波长)照射下处理2h,直至颜色由淡黄色变成深蓝色,得到非化学计量比三氧化钨(WO3-X)。
光催化条件下环己烷的催化转化:
以上述合成的三氧化钨为催化剂,取50mg装入石英反应池进行催化性能评价。在常温常压下首先将环己烷与氧气按2:1比例混合,然后将混合气通过装载有光催化剂的石英反应池,混合气的流量为700mL h-1g催化剂 -1(按光照面积为1cm2计算),光催化过程使用氙灯为模拟太阳光源,光照强度为0.5W cm-2。同时利用气相色谱分析气体产物,结果表明环己烯生成,生成速率为10mmol h-1g-1,环己烯的选择性几乎为100%。
Claims (9)
1.一种高选择性光催化环己烷脱氢制备环己烯的方法,其特征在于:在常温常压下将环己烷与氧气混合,以非化学计量比三氧化钨作光催化剂,在光照下催化环己烷发生脱氢反应生成环己烯,所述的非化学计量比三氧化钨结构式为WO3-X,WO3-X中存在氧空位。
2.根据权利要求1所述的方法,其特征在于:所述的环己烷与氧气的混合气的流量按光照面积为1cm2计算,为600 ~ 1800 mL· h-1 ·g催化剂 -1。
3.根据权利要求1所述的方法,其特征在于:环己烷与氧气混合的体积比为1:1 ~ 2:1。
4.根据权利要求1所述的方法,其特征在于:所述的光照为使用氙灯为模拟太阳光源,光照强度为0.4~0.7 W ·cm-2。
5.根据权利要求1所述的方法,其特征在于:具体步骤为:首先在常温常压下将环己烷与氧气按比例混合,然后将混合气通入装载有光催化剂的石英反应池内,在光照下进行连续流动催化反应,催化环己烷发生脱氢反应生成环己烯,不使用其它辅助加热装置。
6.根据权利要求1所述的方法,其特征在于:所述的非化学计量比三氧化钨WO3-X是将WO3进行紫外照射处理得到,所述紫外照射波长为300~360纳米,功率为50~100W。
7.根据权利要求6所述的方法,其特征在于:所述的紫外照射处理时间1~2h,紫外灯照射处理至颜色由淡黄色变成深蓝色。
8.根据权利要求6所述的方法,其特征在于:所述的WO3为商业WO3;或为采用以下方法自制得到的WO3纳米线:配置钨酸钠水溶液,调节体系的pH至1~2,继续搅拌直到淡黄色沉淀不再产生,随后加硫酸钾,继续搅拌得到乳白色溶液,然后将上述乳白色溶液转移至内衬聚四氟乙烯的不锈钢反应釜中,密封后在170~190℃下反应20~30h,后处理得到WO3纳米线,纳米线的直径为50~80nm。
9.根据权利要求8所述的方法,其特征在于:所述钨酸钠和硫酸钾的质量比为2~3:6~10。
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CN104874389A (zh) * | 2015-05-05 | 2015-09-02 | 上海应用技术学院 | 一种具有氧空位介孔WO3-x可见光催化剂及其制备方法和应用 |
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Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
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Non-Patent Citations (4)
Title |
---|
Electrochromic and photoelectrochemical behavior of electrodeposited tungsten trioxide films;L. Su et al.;《Solar Energy Materials & Solar Cells》;19990621;第58卷;第133-140页 * |
Large-scale hydrothermal synthesis of WO3 nanowires in the presence of K2SO4;Xu Chun Song et al.;《Materials Letters》;20061230;第61卷;第3904–3908页 * |
Visible and infrared photochromic properties of amorphous WO3-x films;Yeon-Gon Mo等;《J. Vac. Sci. Technol. A》;19990909;第17卷(第5期);第2933-2938页 * |
Yeon-Gon Mo等.Visible and infrared photochromic properties of amorphous WO3-x films.《J. Vac. Sci. Technol. A》.1999,第17卷(第5期),第2933-2938页. * |
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