Carbon dioxide is the primary carbon source in the atmosphere and provides the basis for all organic matter on earth. Even though CO 2 is abundant, cheap, and relatively nontoxic compared to the alternative C 1 source carbon monoxide, it is the latter species that is used as a raw material in many bulkscale chemical processes. One promising approach to overcoming the low reactivity of CO 2 [1] is its activation by catalytic hydrogenation to form formic acid or its derivatives. [2] Until now, noble-metal catalysts based on rhodium, [3,4] ruthenium, [5][6][7] and iridium [8,9] were mostly used for this transformation. Graf and Leitner had already achieved significant turnover numbers (TONs) of 3400 with rhodium phosphine complexes in the early 1990s. [3] Jessop, Ikariya, and Noyori were able to increase the catalyst efficiency by using a Ru II complex in supercritical CO 2 (scCO 2 ). [5,6] Very recently, Nozaki and co-workers used a pincer-type Ir III catalyst for the hydrogenation of CO 2 which gave the highest TON reported so far. [9] Much less work on the biologically relevant reduction of carbonates and bicarbonates has been reported, and the reported activities of hydrogenation catalysts are significantly lower compared to the reaction of CO 2 . For example, Joó and co-workers obtained a TON of 108 with [{RuCl 2 -(mTPPMS) 2 } 2 ] (mTPPMS = meta-monosulfonated triphenylphosphine) in aqueous solution. [10] An important long-standing goal in chemistry is the development of bio-inspired catalysis and the replacement of noble metal based catalysts, that is, ruthenium, iridium, and rhodium, with nonprecious metals, such as iron, zinc, and manganese. [11] In this respect, an iron-based reduction of