Han Ye-Chuang, Yi Jun, Pang Beibei, Wang Ning, Li Xu-Cheng, Yao Tao, Novoselov Kostya S, Tian Zhong-Qun
State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Graphene Industry and Engineering Research Institute, School of Electronic Science and Engineering, Xiamen University, Xiamen 361005, China.
Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen 361005, China.
Natl Sci Rev. 2023 Mar 23;10(6):nwad081. doi: 10.1093/nsr/nwad081. eCollection 2023 Jun.
Thermally activated ultrafast diffusion, collision and combination of metal atoms comprise the fundamental processes of synthesizing burgeoning subnanometer metal clusters for diverse applications. However, so far, no method has allowed the kinetically controllable synthesis of subnanometer metal clusters without compromising metal loading. Herein, we have developed, for the first time, a graphene-confined ultrafast radiant heating (GCURH) method for the synthesis of high-loading metal cluster catalysts in microseconds, where the impermeable and flexible graphene acts as a diffusion-constrained nanoreactor for high-temperature reactions. Originating from graphene-mediated ultrafast and efficient laser-to-thermal conversion, the GCURH method is capable of providing a record-high heating and cooling rate of ∼10°C/s and a peak temperature above 2000°C, and the diffusion of thermally activated atoms is spatially limited within the confinement of the graphene nanoreactor. As a result, due to the kinetics-dominant and diffusion-constrained condition provided by GCURH, subnanometer Co cluster catalysts with high metal loading up to 27.1 wt% have been synthesized by pyrolyzing a Co-based metal-organic framework (MOF) in microseconds, representing one of the highest size-loading combinations and the quickest rate for MOF pyrolysis in the reported literature. The obtained Co cluster catalyst not only exhibits an extraordinary activity similar to that of most modern multicomponent noble metal counterparts in the electrocatalytic oxygen evolution reaction, but is also highly convenient for catalyst recycling and refining due to its single metal component. Such a novel GCURH technique paves the way for the kinetically regulated, limited diffusion distance of thermally activated atoms, which in turn provides enormous opportunities for the development of sophisticated and environmentally sustainable metal cluster catalysts.
热激活的金属原子超快扩散、碰撞和结合是合成用于各种应用的新兴亚纳米金属簇的基本过程。然而，到目前为止，还没有一种方法能够在不影响金属负载量的情况下实现亚纳米金属簇的动力学可控合成。在此，我们首次开发了一种石墨烯限制的超快辐射加热（GCURH）方法，用于在微秒内合成高负载金属簇催化剂，其中不可渗透且灵活的石墨烯充当高温反应的扩散受限纳米反应器。源于石墨烯介导的超快高效激光-热转换，GCURH方法能够提供创纪录的高达约10°C/s的加热和冷却速率以及高于2000°C的峰值温度，并且热激活原子的扩散在石墨烯纳米反应器的限制范围内受到空间限制。结果，由于GCURH提供的动力学主导和扩散受限条件，通过在微秒内热解钴基金属有机框架（MOF）合成了金属负载量高达27.1 wt%的亚纳米钴簇催化剂，这代表了已报道文献中最高的尺寸-负载组合之一以及MOF热解的最快速率。所获得的钴簇催化剂不仅在电催化析氧反应中表现出与大多数现代多组分贵金属催化剂相当的非凡活性，而且由于其单一金属组分，在催化剂回收和提纯方面也非常方便。这种新颖的GCURH技术为热激活原子的动力学调控、有限扩散距离铺平了道路，进而为开发复杂且环境可持续的金属簇催化剂提供了巨大机遇。
