Abstract This work is designed to examine the size and composition effects of the pure and Ag-modified Pd nanoclusters on the activity and selectivity of HCOOH decomposition using DFT calculations and microkinetic modeling, Pdn(n = 13,38,55) and Agm@Pdn(m + n = 13,38,55) nanoclusters are considered. The results show that HCOOH decomposition dominantly undergoes COOH intermediate instead of HCOO intermediate, and CO2 formation is more favorable than CO formation. The pure and Ag-modified Pd nanoclusters with the small size exhibit higher activity and selectivity toward CO2 formation; meanwhile, when the nanocluster size is the same, compare to the pure Pd, the Ag composition improves the activity and selectivity toward CO2 formation, and decreases the usage of noble-metal Pd. The better catalytic performance is attributed to that the d-band center is more close to the Fermi level. The results provide a method for improving catalytic performance of Pd-based nanoclusters by adjusting the size and core composition of the nanocluster.

中文翻译：

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HCOOH 在纯和 Ag 修饰的 Pd 纳米团簇上的分解：深入了解团簇大小和组成对活性和选择性的影响

摘要 本工作旨在使用 DFT 计算和微动力学模型、Pdn(n = 13,38,55) 和 Agm@Pdn，研究纯的和 Ag 修饰的 Pd 纳米团簇的大小和组成对 HCOOH 分解的活性和选择性的影响。 (m + n = 13,38,55) 纳米团簇被考虑。结果表明，HCOOH分解主要发生COOH中间体而不是HCOO中间体，并且CO2的形成比CO的形成更有利。纯的和Ag修饰的小尺寸Pd纳米团簇对CO2的形成表现出更高的活性和选择性；同时，当纳米团簇尺寸相同时，与纯 Pd 相比，Ag 组合物提高了对 CO2 形成的活性和选择性，并减少了贵金属 Pd 的使用。更好的催化性能归因于d带中心更接近费米能级。该结果为通过调整纳米团簇的尺寸和核组成来提高钯基纳米团簇的催化性能提供了一种方法。