Function-Integrated Ru Catalyst for Photochemical CO₂ Reduction

Abstract

Visible-light-driven catalytic reduction of CO2 is at the heart of artificial photosynthesis. Here, we demonstrate the first example of a Ru complex that can function both as a photosensitizer and catalyst for CO2 reduction. The catalyst exhibited excellent activity for CO evolution with a high turnover number (TON, 353 for 24 h), reaction rate (TOF, 14.7 h–1), and product selectivity (97%) under visible-light irradiation. We also succeeded in selective product formation (CO or HCOOH) by changing the basicity of the reaction media. This finding will open new avenues for visible-light-driven photoredox catalysis using Ru-based function-integrated photocatalysts.

Structure Function Relationships in Ruthenium Carbon Dioxide Reduction Catalysts with CNC Pincers Containing Donor Groups

“…Notably the current studies have been conducted at lower concentrations of catalyst than the prior studies which is in line with current literature trends (1 µ m vs. 100 µ m ). [2c], [4c], Evaluating catalysts at lower concentration is desirable to avoid SD limited catalysis since the solubility limit of BIH in MeCN is around 10 m m . The observed trend in catalyst TON is Ru OMe > Ru Me > Ru 3OMe > Ru H > Ru NPh2 >> Ru NMe2 > Ru OH (Figure , Table ).…”

Controlling Spin‐Correlated Radical Pairs with Donor–Acceptor Dyads: A New Concept to Generate Reduced Metal Complexes for More Efficient Photocatalysis

“…Most studies on visible-light driven photoredoxc atalysis completely ignore the efficiency aspect (i.e.,t he overall quantum yields) and merely focus on the feasibility to use visible light as energy input. In addition to photoredox catalysis, the M À generation is important for many photochemical carbon dioxide reduction [12,[81][82][83] and hydrogen production [13,[84][85][86][87][88][89][90][91][92] mechanisms, demonstrating that the new mechanism introduced in this manuscript has severalp ossible application areas. Our study on the heavily underexplored inherente ffi-ciency of photoinduced electron transfer events might trigger furtherq uantitative investigations that could contribute to a better understanding of how to use photons moree fficiently, [93] which could ultimately result in more sustainability in photochemistry.…”

“…Visible-light photoredox catalysis as av ersatile tool in synthetic organic chemistry has attracted increasing attention in recent years, [1][2][3][4][5][6][7][8] and research on solar fuels continues to explore the possibility of harvesting sunlight to drive chemical reactions. [9][10][11][12][13] About half of the chemical syntheses in these fields are reductivet ransformations, with the most prominentk ey intermediates for substrate activation being one-electron-reduced Ru and Ir metal complexes.H owever,t he direct generation of thesei ntermediates via photoreduction of excited triplet states is usually inefficient, which is due to the heavy atom effect. Hence, as ubstantial part of the photons absorbed by the catalyst cannotb eu sed productively,a dversely affecting the sustainabilitya spect connected with photocatalysis.…”

Visible‐Light Photocatalytic Reduction of CO2 to Formic Acid with a Ru Catalyst Supported by N,N′‐Bis(diphenylphosphino)‐2,6‐diaminopyridine Ligands

“…Success in this endeavor requires confronting the inherent stabilitya nd low thermodynamic value of CO 2 and would transform this ubiquitous waste product into av aluable feedstock. [15,16] Recently,p incer ligand-supported catalysts of Fe, Co, Ru, and Ir have been shown to have excellent activity and selectivity for hydrogenation of CO 2 . Furthermore, formic acid has been identified and explored as ap otential carrier of dihydrogen.…”

“…For example, photocatalytic formation of formic acid, at wo-electron reductionp roduct of CO 2 ,w ould yield ac ommodity chemical and al iquid fuel. [15,16] Recently,p incer ligand-supported catalysts of Fe, Co, Ru, and Ir have been shown to have excellent activity and selectivity for hydrogenation of CO 2 . [1,2] Homogeneous catalysts have been developed for CO 2 reduction under both electrochemical and photochemical conditions.…”