英语翻译This is obtained mostly by preventing sidereactions from occurring through a limitation of the contactbetween the catalyst and the reacting mixture.Figure 6 clearlyshows that a short enough contact time is required to achieve agood select

英语翻译This is obtained mostly by preventing sidereactions from occurring through a limitation of the contactbetween the catalyst and the reacting mixture.Figure 6 clearlyshows that a short enough contact time is required to achieve agood select
英语翻译
This is obtained mostly by preventing side
reactions from occurring through a limitation of the contact
between the catalyst and the reacting mixture.Figure 6 clearly
shows that a short enough contact time is required to achieve a
good selectivity,but excessively short will compromise the
production rate.On the other side,a longer contact time,which
maximizes the production rate,results in a detrimental effect
on selectivity.
Consideration of the residence time can be reformulated in
terms of reaction mechanism progress along the catalyst bed.
The above evidence allows speculation that only reactions of
H2O2 direct synthesis and water formation occur in the first part
of the catalytic bed,due to the low concentration of H2O2.It is
reported19,28,31,32 that completely oxidized Pd2+ (likely in the
form of PdO) preferentially supports water formation instead
of H2O2 synthesis in the absence of promoters (as we operate).
Since oxygen is fed largely exceeding H2,we speculate that a
significant fraction of the irregular palladium clusters could be
indeed Pd2+,notwithstanding the initial reduction pretreatment,
thus favoring water formation.

英语翻译This is obtained mostly by preventing sidereactions from occurring through a limitation of the contactbetween the catalyst and the reacting mixture.Figure 6 clearlyshows that a short enough contact time is required to achieve agood select
这是通过防止侧多得
从接触发生反应的限制
催化剂和反应混合物之间.图6清楚地
表明足够短的接触时间要求达到
选择性好,但过快会妥协的
生产速度.在另一边,一个较长的接触时间,这
最大限度地提高生产率,在不利的结果
选择性研究.
的停留时间可以重新考虑
反应机理的研究进展沿催化剂床上.
上述证据,允许投机,只有反应
直接合成过氧化氢和水的形成发生在fi第一部分
的催化床,由于过氧化氢的低浓度.它是
reported19,28,31,32完全氧化钯（可能在
形式的PDO）优先支持水形成相反
在没有助剂H2O2合成（我们操作）.
由于氧供给大大超过H2,我们推测
不规则的钯团簇显fi斜面部分可以
的确,PD2 +,尽管初始还原预处理,
从而有利于水的形成.