Mengyang Liu, Shaobo Han, Wenna Zhang, Bin Gu*, Jingmei Li, Huangzhao Wei, Xin Rong, Chenglin Sun*
ACS Catal. 2025, 15, 5:
https://doi.org/10.1021/acscatal.4c07243
ABSTRACT: In a propane dehydrogenation (PDH) reaction system, low-Pt catalysts generally suffer from rapid deactivation and poor durability due to easy sintering at high temperatures and in a reductive atmosphere. Herein, we develop a catalyst (PtSnK-B/Al2O3, named as PtSnK-B0.32) with both low Pt loading (0.15 wt %) and high durability by facile doping of trace boron into a conventional Pt-based catalyst. Density functional theory (DFT) calculations show that pure Pt clusters have weak binding energy with support, leading to a further undesired Pt sintering process. In contrast, when boron (B) is added to the Pt-based catalyst, the undesired Pt sintering process is significantly inhibited. Moreover, being initiated by propane molecules, the pure Pt clusters are readily to dissociate into Pt atoms due to their longer Pt-Pt bond lengths, then the dissociated Pt atoms are captured by B or BOx species to form stable Pt–B clusters under PDH conditions. The formation of highly dispersed Pt–B clusters allows the catalyst to achieve high intrinsic activity; compared with the catalyst without B (PtSnK, 0.14 wt % Pt), the Ea value of the B-doped catalyst is obviously reduced. Significantly, the durability of PtSnK-B0.32 is three times that of PtSnK and even twice that of 0.26PtSnK with a Pt loading of 0.26 wt %. The facile synthesis method, lower Pt content, and higher durability provide a promising application perspective.
摘要：在丙烷脱氢（PDH）反应体系中，低铂催化剂通常因在高温和还原性气氛下易发生烧结而面临快速失活和耐久性差的问题。本文通过向传统铂基催化剂中简便地掺杂微量硼，开发出一种兼具低铂负载量（0.15 wt%）和高耐久性的催化剂（PtSnK-B/Al₂O₃，命名为PtSnK-B0.32）。密度泛函理论计算表明，纯铂团簇与载体之间的结合能较弱，会导致进一步的铂烧结过程。相反，当铂基催化剂中加入硼后，不利的铂烧结过程被显著抑制。此外，在丙烷脱氢反应条件下，纯铂团簇由于其较长的铂-铂键键长，易在丙烷分子作用下解离成铂原子，这些解离的铂原子随后被硼或氧化硼物种捕获，形成稳定的铂-硼团簇。高度分散的铂-硼团簇的形成使催化剂具有高本征活性；与未掺硼的催化剂（PtSnK，铂负载量0.14 wt%）相比，掺硼催化剂的活化能明显降低。值得注意的是，PtSnK-B0.32的耐久性是PtSnK的三倍，甚至是铂负载量为0.26 wt%的0.26PtSnK催化剂的两倍。这种简便的合成方法、更低的铂含量以及更高的耐久性为其提供了广阔的应用前景。
