Xu Haidi, Zhang Zihao, Liu Jixing, Do-Thanh Chi-Linh, Chen Hao, Xu Shuhao, Lin Qinjing, Jiao Yi, Wang Jianli, Wang Yun, Chen Yaoqiang, Dai Sheng
Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu, 610064, China.
Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Nat Commun. 2020 Aug 6;11(1):3908. doi: 10.1038/s41467-020-17738-9.
Single-atom catalysts (SACs) have attracted considerable attention in the catalysis community. However, fabricating intrinsically stable SACs on traditional supports (N-doped carbon, metal oxides, etc.) remains a formidable challenge, especially under high-temperature conditions. Here, we report a novel entropy-driven strategy to stabilize Pd single-atom on the high-entropy fluorite oxides (CeZrHfTiLa)O (HEFO) as the support by a combination of mechanical milling with calcination at 900 °C. Characterization results reveal that single Pd atoms are incorporated into HEFO (Pd@HEFO) sublattice by forming stable Pd-O-M bonds (M = Ce/Zr/La). Compared to the traditional support stabilized catalysts such as Pd@CeO, Pd@HEFO affords the improved reducibility of lattice oxygen and the existence of stable Pd-O-M species, thus exhibiting not only higher low-temperature CO oxidation activity but also outstanding resistance to thermal and hydrothermal degradation. This work therefore exemplifies the superiority of high-entropy materials for the preparation of SACs.
单原子催化剂（SACs）在催化领域引起了广泛关注。然而，在传统载体（氮掺杂碳、金属氧化物等）上制备本质稳定的SACs仍然是一项艰巨的挑战，尤其是在高温条件下。在此，我们报道了一种新颖的熵驱动策略，通过机械研磨与900°C煅烧相结合的方法，将钯单原子稳定在高熵萤石氧化物（CeZrHfTiLa）O（HEFO）作为载体上。表征结果表明，单个钯原子通过形成稳定的Pd-O-M键（M = Ce/Zr/La）掺入HEFO（Pd@HEFO）亚晶格中。与传统载体稳定的催化剂如Pd@CeO相比，Pd@HEFO具有更高的晶格氧还原能力和稳定的Pd-O-M物种，因此不仅表现出更高的低温CO氧化活性，而且具有出色的抗热和抗水热降解性能。因此，这项工作例证了高熵材料在制备SACs方面的优越性。
