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

提出的用于从木质纤维素生产液体燃料的路线的显著部分需要在水中操作的非均相催化剂。虽然为石油转化化学开发的常规非均相催化剂能够催化这些转化中的许多种，但是这些催化剂的活性、选择性和稳定性未被优化，并且催化剂的所有三种性质将在一定程度上受到溶剂化效应的影响。缺乏对生物质转化化学过程中溶剂化作用的理解阻碍了我们设计优化的生物燃料生产催化剂和工艺的能力。水在生物质转化催化中的作用不仅对材料选择有影响，而且可以通过水溶剂化作用使吸附的反应物和过渡态稳定或不稳定来影响催化活性和选择性。宾夕法尼亚州大学公园的宾夕法尼亚州立大学的Robert Rioux教授提出了一项研究计划来解决这一问题。他的假设是，具有定制疏水性的非均相催化剂将表现出更高的生物质衍生原料转化活性。他认为，通过选择配体来有效地调整活性位点周围的环境可以减少水抑制的影响，并且非均相催化剂的载体本身可以被认为是配体，因此被修饰以赋予各种水平的疏水性。他将探讨固体酸的疏水改性和协同酸碱非均相催化剂在多大程度上可以最大限度地减少溶剂化效应而不会对催化产生负面影响。拟议的研究是将均相催化与非均相催化结合到催化剂设计框架中，并利用溶液热力学开发高活性和选择性的生物质转化催化剂用于水相处理。该提案范围内的研究项目将通过大学的MURE和WISER方案提供给女大学生和代表性不足的群体。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公众传播，以展示影响催化剂技术在生物质转化为生物燃料中的作用。总的来说，Rioux的提案强调了多相催化在将生物质转化为可持续的可再生能源方面的重要作用。

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.