Advances in the essential direct hydrogenation of CO2 to formic acid are strongly linked to the development of suitable catalytic systems. Here, we have followed the molecular tailoring of macroligands that can be achieved by the crosslinking of aryl phosphine units or of entire transition metal phosphine complexes. Besides the systematic investigation of the reaction parameters, the metal uptake of these macroligands is studied. The versatile crosslinking strategy allows the incorporation of a series of common diphosphines into the frameworks, serving as fixed coordination sites for immobilized ruthenium species. The investigation described here is not restricted to one catalyst, but compares the characteristics and catalytic activities of a wide range of different materials, focusing on their stability over several recycling runs. In particular, catalysts derived from xantphos and BINAP show excellent catalytic performances after a certain induction period. Hence, this study highlights the advantageous properties of rigid bidentate macroligands with spatially close coordination sites for the design of an active and stable solid catalyst in the CO2 hydrogenation to formates.

中文翻译：

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固体分子钌催化剂中膦化氢大分子配体对CO2加氢制甲酸盐的影响


CO2 直接加氢制甲酸的进步与合适的催化系统的开发密切相关。在这里，我们遵循了大配体的分子定制，这可以通过芳基膦单元或整个过渡金属膦复合物的交联来实现。除了系统地研究反应参数外，还研究了这些大分子量配体的金属摄取。多功能交联策略允许将一系列常见的二膦掺入框架中，作为固定化钌物种的固定配位点。这里描述的研究不仅限于一种催化剂，而是比较了各种不同材料的特性和催化活性，重点关注它们在几次回收过程中的稳定性。特别是，源自 xantphos 和 BINAP 的催化剂在一定的诱导期后表现出优异的催化性能。因此，本研究强调了具有空间上接近配位点的刚性双齿大配体的有利特性，用于在 CO2 加氢制甲酸盐中设计活性和稳定的固体催化剂。