中国科学院大连化学物理研究所叶茂团队近日揭示了稳定丙烷脱氢催化剂中铂在沸石中的迁移锁止。2025年5月28日出版的《自然》杂志发表了这项成果。

页岩气革命已将丙烯生产从石脑油裂解转变为以丙烷脱氢（PDH）为主导技术的专用生产。因为PDH是吸热的，需要有利于烧结和焦化的高温，所以挑战在于开发足够稳定的活性和稳定的催化剂。沸石负载的Pt-Sn催化剂已经开发出来，以平衡活性、选择性和稳定性，最近的工作记录了一种基于沸石锚定的单铑原子的PDH催化剂，具有出色的性能和稳定性。

研究组对硅质岩-1（S-1）表明，通过调节S-1晶体b轴的长度，可以控制包封的Pt-Sn₂团簇的迁移，从而控制沸石内的团聚和锚定，以及外表面上的团聚。结果发现，当该轴长于2.00μm时，Pt-Sn₂单体在PDH过程中的迁移导致（Pt-Sn₂）₂二聚体的晶内形成，这些二聚体牢固地锁定在S-1的通道中，能够在550°C下将纯丙烷原料转化为丙烯超过6个月，在91%的平衡转化率下具有98.3%的选择性。

这种性能超过了其他Pt基PDH催化剂，接近Rh基催化剂。虽然合成要求和成本目前对工业用途来说是令人望而却步的，但研究组预计，这种控制沸石中金属迁移和锁定的方法可能有助于开发其他贵金属催化剂，在工业应用中提供更长的使用寿命。 

附：英文原文

Title: Pt migration-lockup in zeolite for stable propane dehydrogenation catalyst

Author: Xu, Zhikang, Gao, Mingbin, Wei, Yao, Yue, Yuanyuan, Bai, Zhengshuai, Yuan, Pei, Fornasiero, Paolo, Basset, Jean-Marie, Mei, Bingbao, Liu, Zhongmin, Zhu, Haibo, Ye, Mao, Bao, Xiaojun

Issue&Volume: 2025-05-28

Abstract: The shale gas revolution has shifted propylene production from naphtha cracking to on-purpose production with propane dehydrogenation (PDH) as the dominant technology1-9. Because PDH is endothermic and requires high temperatures that favour sintering and coking, the challenge is to develop active and stable catalysts1-3 that are sufficiently stable10,11. Zeolite-supported Pt-Sn catalysts have been developed to balance activity, selectivity and stability12,13, and more recent work documented a PDH catalyst based on zeolite-anchored single rhodium atoms with exceptional performance and stability14. Here we show for silicalite-1 (S-1) that migration of encapsulated Pt-Sn2 clusters and hence agglomeration and anchoring within the zeolite versus agglomeration on the external surface can be controlled by adjusting the length of the S-1 crystals’ b-axis. We find that when this axis is longer than 2.00 μm, migration of Pt-Sn2 monomers during PDH results in intra-crystalline formation of (Pt-Sn2)2 dimers that are securely locked in the channels of S-1 and capable of converting pure propane feed to propylene at 550 °C for more than 6 months with 98.3% selectivity at 91% equilibrium conversion. This performance exceeds that of other Pt-based PDH catalysts and approaches that of the Rh-based catalyst. While synthesis requirements and cost are currently prohibitive for industrial use, we anticipate that our approach to controlling the migration and lockup of metals in zeolites may enable to development of other noble metal catalysts that offer extended service lifetimes in industrial applications15-17.

DOI: 10.1038/s41586-025-09168-8

Source: https://www.nature.com/articles/s41586-025-09168-8