Thermodynamic Assessment of the Influence of Inner- and Outer-Sphere Chemical Environment of Heterogeneous Catalysts during the Reforming of Biomass-Derived Oxygenates

从木质纤维素生产液体燃料的提议路线中，有相当一部分需要多相催化剂才能在水中运行。尽管传统的石油转化化学多相催化剂能够催化许多此类转化，但这些催化剂的活性、选择性和稳定性并不是最优的，而且这些催化剂的三个性质都会受到溶剂化效应的一定程度的影响。缺乏对生物质转化化学中溶剂化作用的了解，阻碍了我们为生物燃料生产设计优化催化剂和工艺的能力。水在生物质转化催化剂中的作用不仅对材料的选择有影响，而且可以通过水对吸附的反应物和过渡态的稳定或不稳定来影响催化活性和选择性。宾夕法尼亚州立大学的Robert Rioux教授提出了一项研究计划，以解决这一不足。他的假设是，具有定制疏水性的多相催化剂将在生物质来源的原料转化中显示出更高的活性。他认为，通过选择配体来有效地调整活性中心周围的环境可以减少水抑制的影响，而且从本质上讲，多相催化剂的载体可以被认为是一种配体，因此可以进行修饰以赋予不同程度的疏水性。他将探索固体酸和酸碱协同多相催化剂的疏水改性在不对催化剂产生负面影响的情况下将溶剂化效应降至最低的程度。拟议的研究是将均相催化和多相催化结合到一个具有溶液热力学的催化剂设计框架中，以开发用于水相加工的高活性和选择性的生物质转化催化剂。这项提议范围内的研究项目将通过Mure大学和WISER计划向本科生女性和代表性不足的群体提供。这项工作将通过PI与宾夕法尼亚州能源和环境研究所协调的努力向普通公众传播，以展示催化剂技术在将生物质转化为生物燃料方面所发挥的影响。总体而言，Rioux提案强调了多相催化将在将生物质转化为可持续的可再生能源方面发挥的重要作用。

A significant fraction of the routes proposed for the production of liquid fuels from lignocellulose require heterogeneous catalysts to operate in water. While conventional heterogeneous catalysts developed for petroleum conversion chemistry are capable of catalyzing many of these conversions, the activity, selectivity and stability of these catalysts are not optimized and all three properties of the catalyst will be influenced to some extent by solvation effects. The lack of understanding of the role of solvation during biomass conversion chemistry impedes our ability to design optimized catalysts and processes for biofuel production. The role of water in biomass conversion catalysis not only has implications on materials selection, but can influence catalytic activity and selectivity through the stabilization or destabilization of adsorbed reactants and transition states by water solvation.Professor Robert Rioux at the Pennsylvania State University, University Park, PA, proposes a research program to address this lack. His hypothesis is that heterogeneous catalysts with tailored hydrophobicity will demonstrate higher activity for biomass-derived feedstock conversion. He suggests that effective tailoring of the environment around an active site through the choice of ligand can reduce the influence of water inhibition, and that inherently the support of a heterogeneous catalyst can be considered a ligand and therefore modified to impart various levels of hydrophobicity. He will probe the extent to which hydrophobic modification of solid acid and cooperative acid-base heterogeneous catalysts can minimize solvation effects without negatively influencing catalysis.The proposed research is an integration of homogeneous catalysis with heterogeneous catalysis into a catalyst design framework with solution thermodynamics to develop highly active and selective biomass-conversion catalysts for aqueous phase processing. Research projects within the scope of this proposal will be offered to undergraduate women and underrepresented groups through the university MURE and WISER programs. The work will be disseminated to the general public through an effort the PI is coordinating in conjunction with the Pennsylvania Institutes for Energy and the Environment to demonstrate the impact catalyst technology plays in the conversion of biomass to biofuels. Overall the Rioux proposal highlights the important role heterogeneous catalysis will play in the conversion of biomass into a sustainable, renewable energy source.