The PtIn nanoalloys with high surface energy are generally in a metastable state during harsh reaction conditions, and the ordered alloy structure is not conducive to exposure of surface Pt active sites. Herein, a strategy for restructuring the unfavorable PtIn alloy structure via heteroatom (Ce) doping is applied to advance an isolated Pt^δ+ confined by the InCeO_x nanoislands supported on SiO₂. The as-synthesized catalyst with optimizing PtIn(Ce) ternary components exhibits ∼92.2% selectivity toward propylene and a stable propane conversion of ∼67.1% at 550 °C (k_d of 0.010 h^–1). As demonstrated by the comprehensive characterizations, the introduced proper amount of Ce species leads to the reorganization of the disadvantaged PtIn nanoalloy structure into the robustness of the isolated Pt^δ+ site confined by the InCeO_x nanoislands via inhibiting the In⁰ species generation. The introduced Ce species modulate the electronic interaction between Pt, In, and carrier, stimulating the capability to activate reactive molecules and at the same time acting as spatial physical barriers to restrict the migration of the isolated Pt^δ+ species. This work proposed a facile and efficient strategy to promote the capability against sintering and coking of the Pt-based catalyst in propane dehydrogenation.

中文翻译：

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通过 Ce 辅助约束效应增强 PtIn 催化剂在丙烷脱氢中的作用

具有高表面能的PtIn纳米合金在恶劣的反应条件下通常处于亚稳态，有序的合金结构不利于表面Pt活性位点的暴露。在此，采用通过杂原子（Ce）掺杂来重组不利的PtIn合金结构的策略，以推进由SiO ₂上支撑的InCeO _x^{纳米岛限制的孤立的Pt δ+}。具有优化的 PtIn(Ce) 三元组分的合成催化剂在 550 °C（k _d为 0.010 h ^–1）下对丙烯具有约 92.2% 的选择性和约 67.1% 的稳定丙烷转化率。综合表征表明，引入适量的Ce物种可以通过抑制In ⁰物种的生成，将不利的PtIn纳米合金结构重组为由InCeO _x^{纳米岛限制的孤立Pt δ+}位点的鲁棒性。引入的 Ce 物种调节 Pt、In 和载流子之间的电子相互作用，激发活性分子的激活能力，同时充当空间物理屏障，限制孤立的 Pt ^δ+物种的迁移。这项工作提出了一种简便有效的策略来提高丙烷脱氢中铂基催化剂的抗烧结和结焦能力。