One-pot pyrolysis synthesis of highly active Ru/RuOX nanoclusters for water splitting

Fengyuan Zhu  , Jiangyan Xue  , Lingjian Zeng  , Jingrui Shang , Xueqin Cao  , Hongwei Gu , Jianping Lang  , Shuanglong Lu  , 

Brendan F. Abrahams 

Using simple methods to obtain efficient catalysts has been a long-standing goal for researchers. In this work, the employment of a one-pot pyrolysis reaction to achieve molecular confinement, has led to the preparation of ruthenium (Ru)-based nanoclusters in a carbon matrix. A unique feature of the synthetic approach employed is that solvent and substrates were calcined together. As solvent evaporates, during calcination, the substrates form a dense solid which has the effect of limiting the aggregation of Ru centers during the carbonization process. The catalyst prepared in this simple manner showed an impressively high activity with respect to the hydrogen/oxygen evolution reaction (HER/OER). The Ru nanoclusters (Ru NCs), as the hydrogen evolution reaction (HER) catalysts, require ultralow overpotentials of 5 mV and 5.1 mV at −10 mA·cm⁻² in 1.0 M KOH, and 0.5 M H₂SO₄, respectively. Furthermore, the catalyst prepared by the one-pot method has higher crystallinity, a higher Ru content and an ultrafine cluster size, which contributes to its exceptional electrochemical performance. Meanwhile, the RuO_X nanoclusters (RuO_X NCs), obtained by oxidizing the aforementioned Ru NCs, exhibited good oxygen evolution reaction (OER) performance with an overpotential of 266 mV at 10 mA·cm⁻². When applied to overall water splitting, Ru/RuO_X nanoclusters as the cathode and anode catalysts can reach 10 mA·cm⁻² at cell voltages of only 1.49 V in 1 M KOH.

用于水分解的高活性 Ru/RuOX 纳米团簇的一锅热解合成

使用简单的方法获得高效的催化剂一直是研究人员的长期目标。在这项工作中，采用一锅热解反应来实现分子限制，导致在碳基质中制备了基于钌 (Ru) 的纳米团簇。所采用的合成方法的一个独特特征是将溶剂和底物一起煅烧。随着溶剂蒸发，在煅烧过程中，基材形成致密的固体，其具有限制碳化过程中 Ru 中心聚集的作用。以这种简单方式制备的催化剂在氢/氧析出反应 (HER/OER) 方面表现出令人印象深刻的高活性。Ru纳米团簇（Ru NCs）作为析氢反应（HER）催化剂，在-10 mA·cm时需要5 mV和5.1 mV的超低过电位-2 分别在 1.0 M KOH 和 0.5 MH 2 SO 4 中。此外，通过一锅法制备的催化剂具有更高的结晶度、更高的 Ru 含量和超细的团簇尺寸，这有助于其优异的电化学性能。同时，通过氧化上述Ru NCs获得的RuO X纳米团簇（RuO X NCs）表现出良好的析氧反应（OER）性能，在10 mA·cm -2 下的过电位为266 mV 。当应用于整体水分解时，作为阴极和阳极催化剂的Ru/RuO X纳米团簇可以在 1 M KOH 中仅 1.49 V 的电池电压下达到 10 mA·cm -2。

DOI: 10.1007/s12274-021-3590-x