Effects of boron and fluorine modified γ-Al2O3 with tailored surface acidity on catalytic ethanol dehydration to ethylene
Effects of boron and fluorine modified γ-Al2O3 with tailored surface acidity on catalytic ethanol dehydration to ethylene
复制标题
DOI：
10.1007/s10934-017-0522-y
复制
发表时间：
2018-08
影响因子：
2.6
通讯作者：
Rui Feng;Xinlong Yan;Xiaoyan Hu
中科院分区：
文献类型：
--
作者：
Rui Feng;Xinlong Yan;Xiaoyan Hu
研究了硼、氟改性γ-Al2O3在乙醇脱水制乙烯过程中的作用。采用溶胶-凝胶法制备了常规和改性γ-Al2O3，并对其进行了表征。结果表明，随着硼含量的增加，γ-Al2O3表面的刘易斯酸量减少。随着氟含量的增加，改性后的γ-Al2O3产生了新的Brönsted酸中心，导致Brönsted酸中心和刘易斯酸中心共存，同时出现了强酸中心。硼改性γ-Al2O3催化剂（Al-B1）在340 ° C下对乙醇转化为乙烯具有良好的催化稳定性和选择性。硼改性后催化剂的酸性降低是催化剂稳定性提高的主要原因。结果表明，在γ-Al2O3催化剂上，强酸中心尤其是Brönsted酸中心是催化剂失活的主要原因，不利于乙醇脱水制乙烯。
The effect of boron and fluorine modified γ-Al2O3was investigated during ethanol dehydration to ethylene. The conventional and modified γ-Al2O3were prepared by a sol–gel method and characterized by various techniques. The results showed that boron modified γ-Al2O3possessed decreased amount of Lewis acid sites by increasing the boron content. Fluorine modified γ-Al2O3created new Brönsted acid sites with increasing the fluorine content, which resulted in the coexistence of Brönsted and Lewis acid sites, at the same time, strong acid sites appeared. Boron modified γ-Al2O3catalyst (Al-B1) at 340 °C exhibited excellent catalytic stability and good selectivity for ethanol conversion to ethylene. The improvement in the catalytic stability could be attributed to the lower acidity after boron modification. The results indicated that on γ-Al2O3catalyst, strong acid sites especially Brönsted acid sites were responsible for coking deactivation and unfavorable to ethanol dehydration to ethylene.