Lin Le, Zeng Zhenhua, Fu Qiang, Bao Xinhe
Shanghai Advanced Research Institute, Chinese Academy of Sciences Shanghai 201203 China.
State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences Dalian 116023 China
Chem Sci. 2021 Nov 4;12(46):15284-15290. doi: 10.1039/d1sc04428a. eCollection 2021 Dec 1.
Tuning surface reactivity of catalysts is an effective strategy to enhance catalytic activity towards a chemical reaction. Traditional reactivity tuning usually relies on a change of the catalyst composition, especially when large-scale tuning is desired. Here, based on density functional theory calculations, we provide a strategy for flexible large-scale tuning of surface reactivity, from a few tenths of electronvolts (eV) to multiple eV, merely through manipulating the phase, thickness, and support of two-dimensional (2D) ZnO films. 2D ZnO films have three typical phases, graphene, wurtzite, and body-centered-tetragonal structures, whose intrinsic stability strongly depends on the thickness and/or the chemical nature of the support. We show that the adsorption energy of hydrogen differs by up to 3 eV on these three phases. For the same phase, varying the film thickness and/or support can lead to a few tenths of eV to 2 eV tuning of surface reactivity. We further demonstrate that flexible large-scale tuning of surface reactivity has a profound impact on the reaction kinetics, including breaking the Brønsted-Evans-Polanyi relationship.
调节催化剂的表面反应性是提高化学反应催化活性的有效策略。传统的反应性调节通常依赖于催化剂组成的改变，尤其是在需要大规模调节时。在此，基于密度泛函理论计算，我们提供了一种灵活地大规模调节表面反应性的策略，仅通过操纵二维（2D）ZnO薄膜的相、厚度和载体，就能将表面反应性从十分之几电子伏特（eV）调节到多个eV。二维ZnO薄膜有三种典型相，即石墨烯相、纤锌矿相和体心四方结构相，其固有稳定性强烈依赖于薄膜厚度和/或载体的化学性质。我们表明，在这三种相上氢的吸附能差异高达3 eV。对于同一相，改变薄膜厚度和/或载体可导致表面反应性在十分之几eV到2 eV范围内调节。我们进一步证明，表面反应性的灵活大规模调节对反应动力学有深远影响，包括打破布朗斯特-埃文斯-波兰尼关系。
