Reporter: Zhang Lei Supervisor: Prof. Mo Prof. Wang and Prof. Zhang Date:

Outline 1.Introduction 2.Recent Developments in CO2 Hydrogenation to Formate 3.Formic Acid Dehydrogenation with Various Metal Complexes 4.Interconversion of CO2 and Formic Acid 5.Recent Developments in CO2 Hydrogenation to Methanol 6.Summary and Future Outlook 2

Outline 1.Introduction 2.Recent Developments in CO2 Hydrogenation to Formate 3.Formic Acid Dehydrogenation with Various Metal Complexes 4.Interconversion of CO2 and Formic Acid 5.Recent Developments in CO2 Hydrogenation to Methanol 6.Summary and Future Outlook 3

1.Introduction High concentration of CO2 Utilization of CO2 Methods 4 Climate change Rising sea levels Photochemical CO2 reduction Electrochemical CO2 reduction CO2 hydrogenation Artificial photosynthesis Bulk electrolysis Using solar-produced H2 Reaction of metal oxides at extremely high temperature

1.Introduction Photochemical CO2 reduction 5

1.Introduction Photochemical CO2 reduction 6 Sato, S. et al., J. Am. Chem. Soc. 2011, 133, 15240− TON 17(24h)

1.Introduction 7 Photochemical CO2 reduction Sekizawa, K.; Ishitani, O. et al., J. Am. Chem. Soc. 2013, 135, 4596−4599. TON 41(9h)

1.Introduction Limitations including: (i) low turnover numbers and low turnover frequencies (ii) product selectivity (i.e., CO, formate, H2,and other minor products); (iii) use of precious metal catalysts; (iv) use of organic solvents and sacrificial reagents; (v) controlling the pH; (vi) the requirement of coupling oxidative and reductivehalf- reactions. 8 Photochemical CO2 reduction

1.Introduction Electrochemical CO2 reduction Main production is CO CO2 hydrogenation Main aim: hydrogen storage Main production: HCOOH,CH3OH Thermal data: 9

1.Introduction CO2 hydrogenation 10 The thermal reduction

1.Introduction 11 (1)CO2 hydrogenation to formate; (2) Formic acid (FA) dehydrogenation; (3) interconversion of CO2 and formic acid; (4) CO2 hydrogenation to methanol.

2.CO2 Hydrogenation to Formate 2.1. Catalysts with Phosphine Ligands 2.2. Catalysts with Pincer Ligands 2.3. Catalysts with N-Heterocyclic Carbene Ligands 2.4. Half-Sandwich Catalysts with/without Proton- Responsive Ligands Electronic Effects Second-Coordination-Sphere Effects Mechanistic Investigations pH-Dependent Solubility and Catalyst Recovery 12

2.1. Catalysts with Phosphine Ligands Pioneering work 13 Solvent effect Inoue, Y. et al., Chem. Lett. 1976, 863−864. Ezhova, N. N. et al., Russ. Chem. Bull. 2002, 51, 2165−2169.

2.1. Catalysts with Phosphine Ligands The role of water 14 Tsai, J. C.; Nicholas, K. M. J. Am. Chem. Soc. 1992, 114,5117−5124. NBD

2.1. Catalysts with Phosphine Ligands Water-soluble catalysts Gassner, F.; Leitner, W. J. Chem. Soc.,Chem. Commun. 1993, 1465−1466. Horvath, H.; Laurenczy, G.; Katho, A. J. Organomet.Chem. 2004, 689, 1036−1045. Mechanism

2.1. Catalysts with Phosphine Ligands Nonprecious-metal catalysts 16 Federsel, C.; Beller, M. et al., Chem. - Eur. J. 2012, 18, 72−75.

2.1. Catalysts with Phosphine Ligands Combination of scCO2 and ionic liquid (IL) 17 TON 1970, TOF 295/h Wesselbaum, S.; Hintermair, U.; Leitner, W. Angew. Chem., Int. Ed. 2012, 51, 8585−8588.

2.1. Catalysts with Phosphine Ligands 18 Novel protocols Xu, Z.; Hicks, J. C. et al., ChemCatChem 2013, 5, 1769−1771. TON 2800(20h)

2.2. Catalysts with Pincer Ligands 19 Tanaka, R.; Nozaki, K. et al., J. Am. Chem. Soc. 2009, 131, 14168− Tanaka, R.; Nozaki, K. et al., Organometallics. 2011, 30, 6742−6750.

2.2. Catalysts with Pincer Ligands 20 Tanaka, R.; Nozaki, K. et al., Organometallics. 2011, 30, 6742−6750.

2.2. Catalysts with Pincer Ligands Secondary coordination sphere interaction (1)proton-responsive ligands; (2) electro-responsive ligands; (3) ligands that can provide a hydrogen bonding functionality; (4) photoresponsive ligands that exhibit a useful change in properties upon irradiation; (5)NADH-type ligands that can work as a hydride source; (6)hemilabile ligands that provide a vacant coordination site. 21

2.2. Catalysts with Pincer Ligands 22 Hydrogen bonding functionality Schmeier, T. J.; Hazari, N. et al., J. Am. Chem. Soc. 2011, 133, 9274−9277.

2.2. Catalysts with Pincer Ligands 23 Nonprecious metals Langer, R.; Milstein, D. et al., Angew. Chem., Int. Ed. 2011, 50, 9948−9952.

2.2. Catalysts with Pincer Ligands 24 Filonenko, G. A.; Pidko, E. A. et al., ChemCatChem 2014, 6, 1526−1530.

2.3. N-Heterocyclic Carbene Ligands 25 Azua, A.; Sanz, S.; Peris, E. Chem. - Eur. J. 2011, 17, 3963−3967. Sanz, S.; Benitez, M.; Peris, E. Organometallics 2010, 29, 275−277.

2.4. Half-Sandwich Catalysts Discovery [Cp*Rh(bpy)Cl]Cl transfer hydrogenation of ketones 26 Himeda, Y. et al., J. Mol. Catal. A: Chem. 2003, 195, 95−100. Electronic Effects

2.4. Half-Sandwich Catalysts Electronic Effects 27 Hammett constants (σp+): the more negative their σp+ value, the stronger is their ability to donate electrons.

2.4. Half-Sandwich Catalysts Electronic Effects 28 Himeda, Y. et al. Organometallics 2007, 26, 702−712. Maenaka, Y.; Suenobu, T.; Fukuzumi, S. Energy Environ. Sci. 2012, 5,7360−7367.

2.4. Half-Sandwich Catalysts Second-Coordination-Sphere Effects 29

2.4. Half-Sandwich Catalysts Second-Coordination-Sphere Effects 30

2.4. Half-Sandwich Catalysts 31 Second-Coordination-Sphere Effects Wang, W.-H.; Himeda, Y. et al., Energy Environ. Sci. 2012, 5, 7923−7926.

2.4. Half-Sandwich Catalysts Mechanistic Investigations 32

2.4. Half-Sandwich Catalysts Kinetic isotope effect (KIE) study [Cp*Ir(4DHBP)(OH2)]2+ D2 in KHCO3/H2O (KIE: 1.19) and in KDCO3/D2O (KIE: 1.20)solution. D2O in H2/KDCO3 (KIE: 0.98). [Cp*Ir(6DHBP)(OH2)]2+ D2O resulted in a larger rate decrease than with D2 (bearing pendant OH groups). RDS 33

2.4. Half-Sandwich Catalysts 34 pH-Dependent Solubility and Catalyst Recovery Himeda, Y. et al., Organometallics 2007, 26, 702−712.

2.4. Half-Sandwich Catalysts pH-Dependent Solubility and Catalyst Recovery 35

3. Formic Acid Dehydrogenation 3.1. Catalysts with Phosphine Ligands Organic Solvent Systems Aqueous Solvent Systems 3.2. Catalysts with Pincer-Type Ligands 3.3. Catalysts with Bidentate C,N-/N,N-Ligands 3.4. Half-Sandwich Catalysts with/without Proton- Responsive Ligands Electronic Effects Pendant-Base Effect Changing RDS of Formic Acid Dehydrogenation Solution pH Changing RDS of Formic Acid Dehydrogenation 3.5. Nonprecious Metals 36

3. Formic Acid Dehydrogenation Thermal data: 37

3.1. Phosphine Ligands Pioneering work 38 Coffey, R. S. Chem. Commun. 1967, 923b. Boddien, A.; Beller, M. et al., Adv. Synth. Catal. 2009, 351, 2517−2520. The role of base

3.1. Phosphine Ligands Facially capping ligand 39 Manca, G.; Beller, M.et al., Organometallics 2013, 32, 7053−7064.

3.1. Phosphine Ligands Facially capping ligand 40

3.1. Phosphine Ligands Base-free FA dehydrogenation 41

3.1. Phosphine Ligands Base-free FA dehydrogenation 42 Oldenhof, S.; Reek, J. N. et al., Chem. - Eur. J. 2013, 19, 11507−11511.

3.1. Phosphine Ligands Aqueous Solvent Systems 43 Fellay, C.; Dyson, P. J.; Laurenczy, G. Angew. Chem., Int. Ed. 2008, 47, 3966−3968.

3.2. Catalysts with Pincer-Type Ligands Mechanism 44 Vogt, M.; Milstein, D. Chem. Sci. 2014, 5, 2043−2051.

3.3. Half-Sandwich Catalysts 45 Barnard, J. H.; Xiao, J. Chem. Sci. 2013, 4, 1234−1244.

3.4. Proton-Responsive Ligands Electronic Effects 46

3.4. Proton-Responsive Ligands Pendant-Base Effect Changing RDS of Formic Acid Dehydrogenation 47

3.4. Proton-Responsive Ligands KIE studies With Proton-Responsive Ligands DCO2D replaces HCO2H--2, D2O replaces H2O--1 Without Proton-Responsive Ligands D2O in place of H2O—2.1 DCO2D instead of HCO2H proton relay incorporating a H2O molecule 48 proton relay incorporating a H2O molecule

3.4. Proton-Responsive Ligands Solution pH Changing RDS of Formic Acid Dehydrogenation 49 KIE studies pH 1.7 DCO2D (KIE: 2.04) D2O (KIE: 1.46) pH 3.5 D2O(KIE: 2.70) DCO2D/DCO2Na(KIE: 1.48)

3.4. Proton-Responsive Ligands 50 Wang, W.-H.; Himeda, Y. ACS Catal. 2015, 5, 5496−5504.

3.4. Proton-Responsive Ligands The thermochemistry 51

3.4. Proton-Responsive Ligands The thermochemistry 52

3.5. Nonprecious Metals 53

3.5. Nonprecious Metals 54 Bielinski, E. A.; Hazari, N.; Schneider, S. J. Am. Chem. Soc. 2014, 136,10234−10237.

3.5. Nonprecious Metals 55 Myers, T. W.; Berben, L. A. Chem. Sci. 2014, 5, 2771−2777.

4. Interconversion of CO2 and Formic Acid 56

4. Interconversion of CO2 and Formic Acid 57 Hull, J. F.; Himeda, Y.; Nat. Chem. 2012, 4, 383−388.

5.CO2 Hydrogenation to Methanol Hydrogenation of Formate, Carbonate, Carbamate, and Urea Derivatives to MeOH 58

5.CO2 Hydrogenation to Methanol 59 Balaraman, E.; Milstein, D. Nat. Chem. 2011, 3, 609−614.

5.CO2 Hydrogenation to Methanol 60 Han, Z.; Ding, K. Angew. Chem., Int. Ed. 2012, 51, 13041−13045.

5.CO2 Hydrogenation to Methanol Catalytic Disproportionation of Formic Acid to MeOH 61 TON200 （ 200h ） Miller, A. J. M.; Goldberg, K. I. Angew. Chem., Int. Ed. 2013, 52, 3981−3984.

5.CO2 Hydrogenation to Methanol Cascade Catalysis of CO2 to MeOH 62 Huff, C. A.; Sanford, M. S. J. Am. Chem. Soc. 2011, 133, 18122−18125.

5.CO2 Hydrogenation to Methanol Direct Hydrogenation of CO2 to MeOH 63 Wesselbaum, S.; Leitner, W. Chem. Sci. 2015, 6, 693−704.

6. Summary and Future Outlook Reduction of CO2 to direct or indirect fuel Three methods, CO2 hydrogenation Phosphine Ligands, Pincer Ligands, Half-Sandwich Catalysts et al. Efficiency, low cost, mild conditions Reduction of CO2 to MeOH 64

Acknowledgement Prof. Mo. Prof. Wang. and Prof. Zhang. PhD Chu. All of you here. Thank You! 65

PPT No.25 我问了一下褚师兄，他和您一样，觉得这种应该 不是氮杂卡宾。这个可能是本篇文献作者归类归 错了。 66

PPT No 作者认为可能机理是上面这样的，主要根据 DFT ，核磁，红外光谱得出的。核 磁中没有氢与 Ru 成键形成的峰；用 IR 可以监测到有 [Ru(κ 3 -triphos Me )-(η 1 - OOCH)(η 2 -OOCH)] 的存在，所以提出了上面的机理。