The method is based on the use of silica-supported metal-precursors for each element of the targeted intermetallic compound. The team chose platinum–zinc alloys to begin with, and accordingly prepared Pt/SiO₂ and ZnO/SiO₂ precursors via incipient wetness impregnation. Such precursors are physically mixed and heated under hydrogen atmosphere in a flow reactor (pictured, panel a), with a stepped thermal profile. At a temperature between 170–350 °C platinum is first reduced under the reactive environment and forms a nucleation site (pictured, panel b). Thus, an increase in temperature to above 350 °C triggers the reduction of the ZnO with the simultaneous migration of mobile zinc atoms to the Pt seed, forming an ordered intermetallic PtZn alloy. Optimization of the synthesis parameters guided by spectroscopic characterization resulted in the formation of an alloy with a specific composition — PtZn_1.4/SiO₂. This material proved to be a very active catalyst for the dehydrogenation of propane to propylene, showing high selectivity under industrially relevant conditions. Thanks to a straightforward regeneration approach, the catalyst was also able to achieve a very good durability for over 1,300 h on stream. The team also extended this atomic gas-migration approach to the preparation of other intermetallic catalysts competent for propane dehydrogenation, including platinum–gallium and plating–indium.

The generality of the method, together with the possibility of preparing ordered structures, make this atomic gas-migration approach an interesting tool for the catalysis community. The successful preparation of intermetallic alloys active for other gas–solid reactions as well as the ability to scale up the synthesis of the desired material remain as questions for future studies to demonstrate the ultimate potential of this synthetic strategy.

该方法基于对目标金属间化合物的每种元素使用二氧化硅负载的金属前驱体。该团队首先选择了铂锌合金，并相应地通过初期湿浸渍制备了 Pt/SiO₂ 和 ZnO/SiO₂ 前驱体。这种前驱体在氢气氛下在流动反应器中物理混合和加热（如图，图 a），具有阶梯式热剖面。在 170–350 °C 的温度下，铂首先在反应性环境中被还原并形成成核位点（如图 b 图）。因此，温度升高到 350 °C 以上会触发 ZnO 的还原，同时移动锌原子迁移到 Pt 晶种上，形成有序的金属间化合物 PtZn 合金。在光谱表征的指导下对合成参数进行优化，形成了具有特定成分的合金 — PtZn_1.4/SiO₂。该材料被证明是丙烷脱氢制丙烯的非常活跃的催化剂，在工业相关条件下表现出高选择性。由于采用了简单的再生方法，该催化剂还能够在超过 1,300 小时的运行时间内实现非常好的耐久性。该团队还将这种原子气体迁移方法扩展到制备其他可用于丙烷脱氢的金属间化合物催化剂，包括铂-镓和电镀-铟。

该方法的通用性，以及准备有序结构的可能性，使这种原子气体迁移方法成为催化界的有趣工具。成功制备具有其他气-固反应活性的金属间化合物合金以及扩大所需材料合成的能力仍然是未来研究的问题，以证明这种合成策略的最终潜力。