钾促进的Cu x O / Cu（111）（x≤2）模型表面上CO 2加氢合成甲醇：合理化钾在催化中的潜力,ACS Catalysis

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钾促进的Cu _x O / Cu（111）（x≤2）模型表面上CO ₂加氢合成甲醇：合理化钾在催化中的潜力
ACS Catalysis ( IF 11.3 ) Pub Date : 2020-03-20 , DOI: 10.1021/acscatal.9b05226
Wenjie Liao ₁ , Ping Liu ₂

Affiliation

据报道，碱可作为非均相催化的促进剂，能够增强催化剂的活性和选择性。在催化剂优化中有效利用碱需要对潜在机理有基本的了解。在这项工作中，我们以钾（K）修饰的Cu _x O / Cu（111）（x≤2）模型表面为例，使用组合密度泛函理论（DFT）合理化了二氧化碳加氢过程中K的性质。）计算和动力学蒙特卡洛（KMC）模拟。我们的结果证明了从Cu（111）到K改性的Cu _x O / Cu（111）时，一氧化碳至甲醇选择性的显着调整。沉积的K ⁺使Cu _x稳定O薄膜在二氧化碳加氢的还原条件下。更重要的是，我们的研究表明，K ⁺充当了选择性调节键合的活性中心，电荷转移的促进剂和电子隧穿的介体。结果，K-改性的Cu _x O / Cu（111）打开了由甲二醇[H ₂ C（OH）₂ ]介导的甲酸途径，以促进二氧化碳向甲醇的选择性转化。我们的研究开发了设计的内在规律，以使用碱金属调节催化性能。

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Methanol Synthesis from CO2 Hydrogenation over a Potassium-Promoted CuxO/Cu(111) (x ≤ 2) Model Surface: Rationalizing the Potential of Potassium in Catalysis

Alkalis have been reported as a promotor in the heterogeneous catalysis, being able to enhance the activity and selectivity of catalysts. The effective utilization of alkalis in catalyst optimization requires the fundamental understanding of the underlying mechanism. In this work, we take a potassium (K)-modified Cu_xO/Cu(111) (x ≤ 2) model surface as a case study to rationalize the nature of K during the carbon dioxide hydrogenation using combined density functional theory (DFT) calculation and the kinetic Monte Carlo (KMC) simulation. Our result demonstrates the significant tuning of selectivity from carbon monoxide to methanol on going from Cu(111) to K-modified Cu_xO/Cu(111). The deposited K⁺ stabilizes the Cu_xO thin film under the reducing condition of carbon dioxide hydrogenation. More importantly, our study reveals that K⁺ acts as an active center for selective tuning in the binding, an accelerator for charge transfer, and a mediator for the electron tunneling. As a result, the K-modified Cu_xO/Cu(111) opens a methanediol [H₂C(OH)₂]-mediated formate pathway to facilitate the selective conversion of carbon dioxide to methanol. Our study develops the intrinsic rules of design to tune the catalytic performance using alkali metals.

更新日期：2020-03-20

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