Rational design of Pt-Pd-Ni trimetallic nanocatalysts for room-temperature benzaldehyde and styrene hydrogenation
Rational design of Pt-Pd-Ni trimetallic nanocatalysts for room-temperature benzaldehyde and styrene hydrogenation
复制标题
室温苯甲醛和苯乙烯加氢Pt-Pd-Ni三金属纳米催化剂的合理设计
DOI：
10.1002/asia.202100472
复制
发表时间：
2021
影响因子：
4.1
通讯作者：
Guo Zhengxiao
中科院分区：
文献类型：
--
作者：
Zheng Tuo;Wu Fengshun;Fu Huan;Zeng Li;Shang Congxiao;Zhu Lihua;Guo Zhengxiao
多金属催化剂的纳米结构为多相催化的微调提供了很大的范围，但是对表面化学和结构的清楚理解对于提高其选择性和效率是重要的。以典型的Pt-Pd-Ni三金属体系为研究对象，比较了浸渍法和电置换法制备的Ni/C、Pt/Ni/C、Pd/Ni/C和Pt-Pd/Ni/C催化剂。为了阐明表面化学/结构效应，在X=200、400或600 °C下在H2还原气氛中对Pt-Pd/Ni/C催化剂进行热处理，分别称为Pt-Pd/Ni/C-X。通过XRD、XPS、TEM、HRTEM、HS-LEIS和STEM-EDS元素图谱和线扫描对所制备的催化剂进行补充表征。对所有催化剂进行了苯甲醛和苯乙烯加氢反应的比较评价。结果表明，与单金属或双金属对应物相比，“镍纳米颗粒上的PtPd合金纳米团簇”（PtPd/Ni）和三金属Pt-Pd-Ni的协同效应导致催化性能大大改善。然而，随着处理温度的升高，Pt-Pd/Ni/C的催化性能逐渐下降，这可能是由于细小的“PtPd/Ni”纳米结构逐渐转变为较大的“PtPdNi合金/Ni”（PtPdNi/Ni）颗粒，从而减少了催化剂表面贵金属（Pt和Pd）活性位的数量。因此，最佳的三金属结构是合成的Pt−Pd/Ni/C。该研究为设计和开发高效、低成本的多金属催化剂提供了一种新的策略。用于氢化反应。
Nanostructures of the multimetallic catalysts offer great scope for fine tuning of heterogeneous catalysis, but clear understanding of the surface chemistry and structures is important to enhance their selectivity and efficiency. Focussing on a typical Pt−Pd−Ni trimetallic system, we comparatively examined the Ni/C, Pt/Ni/C, Pd/Ni/C and Pt−Pd/Ni/C catalysts synthesized by impregnation and galvanic replacement reaction. To clarify surface chemical/structural effect, the Pt−Pd/Ni/C catalyst was thermally treated at X=200, 400 or 600 °C in a H2reducing atmosphere, respectively termed as Pt−Pd/Ni/C−X. The as‐prepared catalysts were characterized complementarily by XRD, XPS, TEM, HRTEM, HS‐LEIS and STEM‐EDS elemental mapping and line‐scanning. All the catalysts were comparatively evaluated for benzaldehyde and styrene hydrogenation. It is shown that the “PtPd alloy nanoclusters on Ni nanoparticles” (PtPd/Ni) and the synergistic effect of the trimetallic Pt−Pd−Ni, lead to much improved catalytic performance, compared with the mono‐ or bi‐ metallic counterparts. However, with the increase of the treatment temperature of the Pt−Pd/Ni/C, the catalytic performance was gradually degraded, which was likely due to that the favourable nanostructure of fine “PtPd/Ni” was gradually transformed to relatively large “PtPdNi alloy on Ni” (PtPdNi/Ni) particles, thus decreasing the number of noble metal (Pt and Pd) active sites on the surface of the catalyst. The optimum trimetallic structure is thus the as synthesised Pt−Pd/Ni/C. This work provides a novel strategy for the design and development of highly efficient and low‐cost multimetallic catalysts, e. g. for hydrogenation reactions.