CO2 Hydrogenation Catalysis

6 Chapter 10Table 10.1 Selective results of FA dehydrogenation.Table 10.2 Selective results of methanol dehydrogenation.

1 Chapter 1 Figure 1.1 Atmospheric CO 2concentration at Mauna Loa Observatory. Figure 1.2 IEA 2 °C Scenario (2DS) in Energy Technology Perspectives 2017.... Figure 1.3 Global methanol demand in 2018. Figure 1.4 CO 2emissions from fuel combustion. Figure 1.5 Low‐carbon electricity generation by source in 2017. Figure 1.6 Levelized cost of energy comparison: Renewable energy versus conv... Figure 1.7 Carbon tax rate per ton of emitted CO 2.

2 Chapter 2 Scheme 2.1 Tautomerizable ligands for functional complexes. Figure 2.1 Proton‐responsive ligands used for CO 2hydrogenation. Figure 2.2 Correlation between initial TOFs and σ p +values of substituents (... Scheme 2.2 Acid–base equilibrium between hydroxy and oxyanion forms and reso... Scheme 2.3 Proposed mechanism for H 2heterolysis assisted by the pendant bas... Figure 2.3 Proton‐responsive N , N ‐ligands with pendant OH groups. Figure 2.4 Selected N , N ‐ligands with NH groups for CO 2hydrogenation. Scheme 2.4 Deprotonation and resonance of N , N ‐ligands with NH groups in comp... Figure 2.5 Selected N , N ‐ligands with OH and NH groups for CO 2hydrogenation.... Scheme 2.5 In situ –prepared and isolated picolinamide complexes for CO 2hydr... Scheme 2.6 Resonance structures of picolinamide complex. Figure 2.6 NHC Ir complexes developed by Peris et al. Figure 2.7 Pincer Ir complexes developed by Nozaki et al. Scheme 2.7 Proposed mechanism for the hydrogenation of CO 2by 7. Figure 2.8 Pincer Ir complexes with NH group. Scheme 2.8 Proposed mechanism for CO 2hydrogenation with 15b. Figure 2.9 Phosphorous ligands and Ru complexes for CO 2hydrogenation. Scheme 2.9 Biphasic system for CO 2hydrogenation developed by Leitner et al.... Figure 2.10 Ru complexes with N , N ‐ and N , O ‐ligands for CO 2hydrogenation. Scheme 2.10 Pincer Ru complexes for H 2and CO 2activation. Scheme 2.11 Experimentally observed transformations of Ru–PNP complexes in t... Scheme 2.12 CO 2hydrogenation with Ru‐CNC pincer complex 41. Figure 2.11 Pincer complexes for CO 2hydrogenation employed by Prakash et al... Scheme 2.13 CO 2capture and conversion to ammonium formate. Scheme 2.14 Integrated CO 2capture and utilization system developed by Praka... Figure 2.12 Ru‐CNC complexes for CO 2hydrogenation. Figure 2.13 Pincer Ru complexes for CO 2hydrogenation. Figure 2.14 Rh complexes and phosphine ligands for CO 2hydrogenation. Scheme 2.15 Biphasic system for CO 2hydrogenation developed by Leitner et al... Figure 2.15 Biometric Rh complexes for CO 2hydrogenation. Figure 2.16 Rh complexes with C , C ‐ and N , N ‐ligands.

3 Chapter 3Figure 3.1 Abundance (ppm) of mid‐ and late transition metals in Earth's cru...Scheme 3.1 Proposed catalytic cycle for CO 2hydrogenation in the presence of...Scheme 3.2 Proposed mechanism for the role of additives in TON enhancement u...Scheme 3.3 Proposed catalytic cycle for CO 2hydrogenation in the presence of...Figure 3.2 Fong and Peters' iron complexes 3–8bearing tri‐ and tetrad...Scheme 3.4 Proposed catalytic cycle for CO 2hydrogenation in the presence of...Figure 3.3 Fe(II) complexes 9and 10bearing the tetradentate phosphine 1,1,...Figure 3.4 NaHCO 3hydrogenation to formate by [FeH( rac ‐P4)] +( 12), path B....Figure 3.5 Fe catalysts derived from Knölker's complex motif.Scheme 3.5 Proposed catalytic cycle for CO 2hydrogenation in the presence of...Scheme 3.6 Proposed catalytic cycle for CO 2hydrogenation showing possible M...Scheme 3.7 Proposed catalytic cycle for CO 2hydrogenation starting from 25....Scheme 3.8 Proposed mechanism for Li co‐catalyst promoting effect starting f...Scheme 3.9 Proposed catalytic mechanism for Li‐assisted CO 2hydrogenation wi...Figure 3.6 Catalyst recycling scheme (a) and observed TOFs (b) using Ru‐MACH...Scheme 3.10 Proposed catalytic mechanism for CO 2hydrogenation with 39.Scheme 3.11 Proposed catalytic cycle for CO 2hydrogenation starting from 41....Scheme 3.12 Proposed catalytic cycle for CO 2hydrogenation starting from 45,...Figure 3.7 Multidentate ligands screened for CO 2hydrogenation in combinatio...Scheme 3.13 Proposed catalytic cycle for CO 2hydrogenation starting from bim...Scheme 3.14 Simplified catalytic cycle for CO 2hydrogenation starting from t...Scheme 3.15 Proposed (simplified) competing catalytic cycles for CO 2hydroge...Figure 3.8 Substituted‐bipyridine Mn(I) bromotricarbonyl complexes 67–70...Scheme 3.16 Proposed catalytic cycles for CO 2hydrogenation in the presence ...Scheme 3.17 Proposed reaction pathway for CO 2functionalization with ethene ...Scheme 3.18 Proposed catalytic cycles for CO 2hydrogenation in the presence ...Scheme 3.19 Synthesis of κ 2‐formato complex 91.

4 Chapter 4Figure 4.1 Carbon‐neutral cycle in the context of methanol economy.Figure 4.2 CO 2hydrogenation to methanol and related reactions.Figure 4.3 Different routes for obtaining methanol from CO 2.Figure 4.4 First reported homogeneous CO 2to methanol system catalyzed by RuFigure 4.5 Step‐wise hydrogenation of CO 2to methanol through carbonate, car...Figure 4.6 Indirect CO 2hydrogenation to methanol through urea derivatives....Figure 4.7 Molecular mechanism of hydrogenation by complex C‐1.Figure 4.8 Indirect CO 2to methanol route through cyclic carbonates.Figure 4.9 Hydrogenation mechanism with complex C‐3.Figure 4.10 Cascade catalysis of CO 2to methanol.Figure 4.11 Ruthenium‐catalyzed CO 2to methanol system developed by Leitner ...Figure 4.12 Mechanistic cycle of CO 2to methanol with C‐8in the absen...Figure 4.13 Cobalt‐catalyzed CO 2to methanol system.Figure 4.14 Combined CO 2capture and conversion to methanol through oxazolid...Figure 4.15 Amine‐assisted CO 2to methanol process.Figure 4.16 Morpholine‐mediated CO 2to methanol through formamide.Figure 4.17 Carbon capture and utilization cycle to form methanol from CO 2....Figure 4.18 PEHA‐assisted CO 2to methanol.Figure 4.19 Conversion of CO 2from air to methanol.Figure 4.20 Biphasic system for catalyst and amine recycling.Figure 4.21 Catalyst and amine recycling based on amine immobilization.Figure 4.22 Change in methanol TON with different substitutions on the P ato...Figure 4.23 Proposed mechanism of amine‐assisted CO 2to methanol process.Figure 4.24 Amine‐assisted CO 2to methanol system reported by Everett and Wa...Figure 4.25 PEI‐mediated CO 2to methanol through formamides.Figure 4.26 Manganese‐catalyzed CO 2hydrogenation to methanol.Figure 4.27 CO 2to methanol via formic acid disproportionation.

5 Chapter 5Figure 5.1 (a) The structural diagrams of the active sites of three types of...Scheme 5.1 Yang and Hall's mechanism for H 2activation catalyzed by [Fe]‐hyd...Figure 5.2 Two typical ways for CO 2insertion into a metal–hydride bond.Scheme 5.2 Two plausible cycles for the dehydrogenation of formic acid catal...Scheme 5.3 Sakaki's mechanism for the hydrogenation of CO 2to formic acid ca...Scheme 5.4 Nozaki and coworkers' plausible mechanism for hydrogenation of COScheme 5.5 Mechanism for the hydrogenation of CO 2catalyzed by (PNP)IrH 3pro...Scheme 5.6 Yang's mechanism for the hydrogenation of CO 2to HCOO −cata...Scheme 5.7 Hazari and coworkers' mechanism for the hydrogenation of CO 2cata...Scheme 5.8 Thiel and coworkers' mechanism for the hydrogenation of CO 2catal...Scheme 5.9 Himeda and coworkers' proton‐switchable iridium catalyst for reve...Scheme 5.10 Himeda and coworkers' mechanism for the hydrogenation of CO 2cat...Scheme 5.11 Mechanism for H 2heterolysis assisted by the pendant base and wa...Scheme 5.12 The transformations of H 2and CO 2catalyzed by (PNP)Ru complexes...Scheme 5.13 Pidko and coworkers' mechanism for CO 2hydrogenation to formates...Scheme 5.14 The overall process of CO 2hydrogenation catalyzed by Ru complex...Scheme 5.15 Proposed overall mechanism for the reduction of bicarbonate to f...Scheme 5.16 Ke and coworkers' mechanism for the hydrogenation of CO 2catalyz...Scheme 5.17 Predicted catalytic cycles with the monohydride (Path I) and dih...Scheme 5.18 Predicted mechanism for CO 2hydrogenation catalyzed by PNP–Fe co...Figure 5.3 The active site structure of [Fe]‐hydrogenase reported by Shima a...Scheme 5.19 Predicted mechanism for the hydrogenation of CO 2to formamide ca...Figure 5.4 Optimized transition state structures of two‐proton transfer for ...Figure 5.5 Liu, Dubois, and Bullock’s Mn (a) and Co (b, c, and d) complexes ...Figure 5.6 Yang and co‐workers' computationally designed Fe (a, b), Mn (c), ...Scheme 5.20 Yang and coworkers' mechanism of the hydrogenation of CO 2to met...Scheme 5.21 Yang and coworkers' mechanism for the hydrogenation of CO 2to fo...Scheme 5.22 Yang and coworkers' mechanism for the hydrogenation of formic ac...Scheme 5.23 Yang and coworkers' mechanism for the hydrogenation of formaldeh...Figure 5.7 Newly constructed iron, cobalt, and manganese complexes [81].Figure 5.8 Meyer's monomeric amidate‐ligated Fe complex (a) [82], Hitomi's m...Scheme 5.24 Yang and coworker's mechanism for the formation of methanol from...Scheme 5.25 Rueping and coworkers' mechanism for the hydrogenation of ethyle...