| 查看: 437 | 回复: 3 | |||
| 当前主题已经存档。 | |||
[交流]
求助将本人的文章译为中文
|
|||
|
首先说明是本人的英文文章，关于材料化学方面，懂得人请进。 During the last decades, the researches of the solid base catalyst in a heterogeneous process have attracted much attention in view of environmental and economical reasons. this is mainly due to the distinct advantange of solid base catalysts such as noncorrosiveness, ease of handling, and easy to recover and reuse. However, Conventional solid bases such as single or binary alkali earth oxide e.g.CaO, CaO/MgO possesses low specific area and are vulnerable to water and carbon dioxide in the air, which to some extent limited the production efficiency in practical application[1; 2; 3].So the modification of the structural and textural characteristics of alkali earth oxides have been extensively studied in terms of catalyst supports and solid solutions .zeolite was utilized as the support to produce strong base through alkali oxide or alkali earth oxide modification [4; 5; 6].However, the drawback of zeolite supported basic catalysts with the small pore openings prevented bulky molecules from reaching the active sites. Hence the use of mesoporous silica SBA-15 as host, direct generation of basicity on mesoporous silica SBA-15 ,in which calcium species were selected as the guest ,have also been proposed[7; 8],whereas the low loading of CaO and relative low water resistance restricted sufficient utilization due to the limited total basicity .Meanwhile the novel solid base ,namely CaO-ZrO2[9]solid solution has been reported in recent years, Obviously, the acidic-basic surface and redox properties of zirconia played the significant roles, and the formed solid solution efficiently prevent the active component from lixiviated into the reaction medium. However, the specific surface area was only 2-31m2g-1and limit the application as the effective solid base catalyst. So Liu[10]subsequently prepared mesoporous CaO-ZrO2 and revealed the prospect of transesterification of esters with methanol as the solid base. However, the preparation suffered from the tedious post treatment, moreover, distinct wormlike mesoporous structure and amorphous framework walls are disadvantageous to mechanical and thermal stability to some extent. Ordered mesoporous structure of CaO-ZrO2 solid solution as a promising solid base has been scarcely reported so far. In this study, we demonstrate a facile approach to incorporating the Ca2+ ion into ZrO2 host to synthesis CaO-ZrO2 solid base with ordered mesoporous structure. And the crystalline wall of CaO-ZrO2 can efficiently improve the thermal and mechanical stability. Based on the view above, the CaO-ZrO2 solid base with ordered mesopore are expected to exert the great effect in catalyst application. |
回复此楼» 猜你喜欢
专硕310求调剂
已经有5人回复
-
081700化学工程与技术 一志愿中海洋 323 求调剂学校
已经有14人回复
-
085600，321分求调剂
已经有5人回复
-
一志愿东北大学085901土木专硕345求调剂
已经有3人回复
-
一志愿哈尔滨工业大学085600英一数二337分求调剂
已经有9人回复
-
工科11408，314求调剂，有项目经验，了解transformer，能训练模型。
已经有3人回复
-
348分环境工程·调剂
已经有11人回复
-
359求调剂
已经有3人回复
-
0703求调剂
已经有6人回复
-
一志愿0817化学工程与技术，求调剂
已经有26人回复
xiaoqihu
铁杆木虫 (著名写手)
- 翻译EPI: 88
- 应助: 1 (幼儿园)
- 贵宾: 0.005
- 金币: 9724.8
- 散金: 7
- 红花: 4
- 帖子: 1337
- 在线: 105.6小时
- 虫号: 590066
- 注册: 2008-08-31
- 专业: 有机合成
xt916820(金币+15):thank you,虽然我已经自己翻译了，但是金币还是全给你了 2010-03-10 12:44
|
在近些年，固体碱催化剂应用于多相催化过程，由于环境问题和经济原因，吸引了更多的关注。固体碱催化剂具有杰出的特性，例如无腐蚀性，易操作，易回收再利用。但是传统的固体碱像单重碱或双重碱土氧化物，例如CaO，CaO/MgO具有很低的specific area，对空气中的水和CO2敏感，这些限制了其在实际领域中的应用。因此对碱土氧化物结构和构造上的修饰被广泛的研究，旨在提供催化剂载体和固体混溶液。zeolite 被用作载体通过碱性氧化物或者碱土氧化物修饰来制备强碱。但是zeolite作为碱性催化剂的载体缺点，其拥有微孔的性质使其阻止了大分子有效地接近活化位点。因此，介孔材料 silica SBA-15 作为主体，直接产生碱性介孔 silica SBA-15 ，其中Ca被选择性的作为客体，这样的理论已经被提出。但是CaO的低负载量导致的有限的碱性和相对低的抗水性限制了其有效的利用。同时，最近报道了新颖的固体碱，CaO-ZrO2固相溶液，很明显，氧化锆的酸-碱表面和还原性质起了很关键的因素，同时形成的固体溶液有效地阻止了活性成分浸出到反应介质中。但是，特异的表面积仅有2-31 m2g-1限制了其作为有效固体碱催化剂的应用。因此Liu最终制备了介孔CaO-ZrO2，其展示了甲醇与酯类进行期望的酯交换反应。但是，制备却要经过冗长的后处理过程，然而像虫一样截然不同的介孔结构和无定形结构壁在某种程度上对力学和热学上稳定性是不利的。 目前具有有序介孔结构的CaO-ZrO2固体溶液作为有希望的固体碱很少有报道。在这项研究中，我们展示了一条便利的将Ca2+引入到 ZrO2 主体去合成有序介孔结构的 CaO-ZrO2 固体溶液的方法。同时CaO-ZrO2 晶体壁可以有效的提高热学和力学的稳定性。基于以上所述，有序介孔CaO-ZrO2固体碱在催化应用领域上可以期待发挥很大的作用。 |
2楼2010-03-08 22:55:11
frank110119
禁虫 (职业作家)
|
本帖内容被屏蔽 |
3楼2010-03-09 08:05:56
xiaoqihu
铁杆木虫 (著名写手)
- 翻译EPI: 88
- 应助: 1 (幼儿园)
- 贵宾: 0.005
- 金币: 9724.8
- 散金: 7
- 红花: 4
- 帖子: 1337
- 在线: 105.6小时
- 虫号: 590066
- 注册: 2008-08-31
- 专业: 有机合成
4楼2010-03-10 03:47:41
