Sahoo Lipipuspa, Dhindsa Parmeet Kaur, P Nihal C, Gautam Ujjal K
Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER)-Mohali Sector 81 SAS Nagar Mohali Punjab 140306 India
Nanoscale Adv. 2021 Feb 17;3(8):2366-2376. doi: 10.1039/d0na01006e. eCollection 2021 Apr 20.
In view of a limited rationale available for designing metal nanocrystals (NCs) to achieve high catalytic activities across various chemical transformations, we offer a new perspective on the optimization of the '' that, to an extent, would help bypass the tedious characterization needs. A systematic improvement in a catalyst is hindered because (i) it relies on size & shape control protocols, surface characterization, understanding molecular transformation mechanisms, and the energetics of the reactant-catalyst interactions, requiring the involvement of different domains experts, and (ii) the insights developed using model reactions may not easily extend to other reactions, although the current studies count on such a hypothesis. In support of (ii), by taking Pd NCs as catalysts and two distinct reaction types, Suzuki coupling and nitroarene reduction, we show to what great extent the reaction rates may vary even for the seemingly similar reactions by using the same NCs. More importantly, for challenge (i), we demonstrate how the addition of a single-step to the current protocol of 'catalyst-synthesis and activity test' can potentially lead to the development of highly active catalysts by first finding a suitable solvent for the NC synthesis, while such solvent-effects are barely considered unlike the same in organic transformation reactions as a matter of routine, for example.
鉴于在设计金属纳米晶体（NCs）以实现各种化学转化的高催化活性方面可用的理论依据有限，我们提供了一种关于优化“ ”的新观点，这在一定程度上有助于绕过繁琐的表征需求。催化剂的系统改进受到阻碍，原因如下：（i）它依赖于尺寸和形状控制方案、表面表征、理解分子转化机制以及反应物 - 催化剂相互作用的能量学，这需要不同领域的专家参与；（ii）尽管当前研究基于这样的假设，但使用模型反应得出的见解可能不容易扩展到其他反应。为支持（ii），以钯纳米晶体作为催化剂，并采用两种不同的反应类型——铃木耦合反应和硝基芳烃还原反应，我们展示了即使使用相同的纳米晶体，对于看似相似的反应，反应速率可能会有多大程度的差异。更重要的是，针对挑战（i），我们展示了如何通过首先为纳米晶体合成找到合适的溶剂，在当前“催化剂合成与活性测试”方案中添加一个步骤，有可能开发出高活性催化剂，而这种溶剂效应与有机转化反应中通常被常规考虑的情况不同，几乎未被考虑。
