Hurtado Salinas Daniel E, Sarasola Ane, Stel Bart, Cometto Fernando P, Kern Klaus, Arnau Andrés, Lingenfelder Magalí
Max Planck-EPFL Laboratory for Molecular Nanoscience, EPFL SB CMNT NL-CMNT, CH 1015 Lausanne, Switzerland.
Institut de Physique, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
ACS Omega. 2019 Jun 5;4(6):9850-9859. doi: 10.1021/acsomega.9b00762. eCollection 2019 Jun 30.
Photosynthesis is the model system for energy conversion. It uses CO as a starting reactant to convert solar energy into chemical energy, i.e., organic molecules or biomass. The first and rate-determining step of this cycle is the immobilization and activation of CO, catalyzed by RuBisCO enzyme, the most abundant protein on earth. Here, we propose a strategy to develop novel biomimetic two-dimensional (2D) nanostructures for CO adsorption at room temperature by reductionist mimicking of the Mg-carboxylate RuBisCO active site. We present a method to synthesize a 2D surface-supported system based on Mg centers stabilized by a carboxylate environment and track their structural dynamics and reactivity under either CO or O exposure at room temperature. The CO molecules adsorb temporarily on the Mg centers, producing a charge imbalance that catalyzes a phase transition into a different configuration, whereas O adsorbs on the Mg center, giving rise to a distortion in the metal-organic bonds that eventually leads to the collapse of the structure. The combination of bioinspired synthesis and surface reactivity studies demonstrated here for Mg-based 2D ionic networks holds promise for the development of new catalysts that can work at room temperature.
光合作用是能量转换的模型系统。它以一氧化碳作为起始反应物，将太阳能转化为化学能，即有机分子或生物质。这个循环的第一步也是限速步骤是一氧化碳的固定和活化，由地球上含量最丰富的蛋白质——核酮糖-1,5-二磷酸羧化酶（RuBisCO）催化。在此，我们提出一种策略，通过简化模拟镁羧酸盐RuBisCO活性位点，开发用于室温下一氧化碳吸附的新型仿生二维（2D）纳米结构。我们展示了一种合成基于由羧酸盐环境稳定的镁中心的二维表面支撑体系的方法，并追踪它们在室温下一氧化碳或氧气暴露条件下的结构动力学和反应活性。一氧化碳分子暂时吸附在镁中心上，产生电荷不平衡，催化相变形成不同构型，而氧气吸附在镁中心上，导致金属-有机键发生畸变，最终导致结构坍塌。本文展示的基于镁的二维离子网络的仿生合成与表面反应性研究相结合，有望开发出可在室温下工作的新型催化剂。
