Formic Acid Dehydrogenation by a Cyclometalatedκ³‐CNN Ruthenium Complex

Abstract

Hydrogen utilization as a sustainable energy vector is of growing interest. We report herein a cyclometalated ruthenium complex [Ru(κ 3 -CNN)(dppb)Cl], originally described by Baratta, to be active in the selective dehydrogenation (DH) of formic acid (FA) to H 2 and CO 2 . TON′s of more than 10000 were [a] 1293 achieved under best conditions without observation of CO (detection limit 10 ppm). The distinguished behavior of the catalyst was explored varying the starting conditions. Our observation revealed the complex [Ru(κ 3 -CNN)(dppb)(OOCH)] as key species in the catalytic cycle. Scheme 1. Selected systems for the Ru catalyzed DH of FA. [21] . Additional phosphine based tridentate ligands were developed such as [Ru(acac) 3 ] in the presence of bis(diphenylphos-Scheme 3. Synthesis of the ligand and Ru-CNN complex.

TowardsoperandoIR‐ and UV‐vis‐Spectro‐Electrochemistry: A Comprehensive Matrix Factorisation Study on Sensitive and Transient Molybdenum and Tungsten Mono‐Dithiolene Complexes**

“…Examples include the active sites of redox-active metalloproteins, [1][2][3][4][5][6][7] many processes in the chemical industry, environmentally relevant transformations such as CO 2 -sequestration [8][9][10][11] and various types of small molecule activation of critical importance for renewable energy technologies such as H 2 O oxidation, [7,[12][13][14][15] N 2 reduction [16][17][18][19][20][21] and H 2 utilisation. [22][23][24][25][26][27][28][29] Consequently, understanding the interplay of redox transitions and chemical modifications in utmost detail is important, particularly when aiming to design and tune catalysts, or control and optimise chemical processes.…”

Efficient additive-free formic acid dehydrogenation with a NNN–ruthenium complex

“…[9][10][11] Impressive results have been achieved with homogeneous systems, even though many are compromised by insufficient productivity in the absence of basic additives. [12][13][14][15][16][17][18][19][20][21][22][23][24][25] Notable exceptions include the systems of Li 26 and Milstein 27 which are active in aqueous solution and neat FA, respectively, and reach turnover frequencies (TOFs) of 487 500 and 3000 h −1 with turnover numbers (TONs) around 2 000 000. Solid supported heterogeneous systems have this far not reached the performance of homogeneous systems, with TOFs around 7000 h −1 .…”