英語翻譯
Thereforedissociative adsorption
of hydrogen is reduced,and hence the chance to have direct
synthesis.19,28,31-33 Hydrogen is more likely to react with the
oxygen present on the Pd2+ surface than with the inner part of
the Pd cluster,with the condition mentioned above16,17,19,20,33,35
(i.e.,an acidic solution or the presence of halides).When contact
time between liquid and solid phases is longer,all the reactions
occur,adding further H2O2 degradation paths.For intermediate
gas and liquid flow rates,production rate is higher and selectivity
achieves very interesting values.Gas solubilization in the liquid
phase plays a key role; it can be modified by using solvent that
selectively increases H2 solubility,34 but also the pressure and
the ratio between gas and liquid flow rates can affect the
concentration of H2 and O2 in the liquid phase.
These observations allow concluding that operative condition
in the TBR may help in controlling the reaction network,in
addition to suitable catalysts,linking the catalyst and the reactor
design and operation.It has been proved that operative condi-
tions play a major role in driving the reactions toward high
selectivity for hydrogen peroxide.The results suggest that
reactor design and operation may be crucial to improve
productivity and selectivity in H2O2 synthesis,together with
developing better catalysts.