3.5 Heterogeneous Catalysts for the Production of Methanol
Derivatives from Methane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
3.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
4 Application of Biocatalysts for the Production of Methanol
from Methane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
4.2 Methane Metabolism in Methane-Oxidizing Bacteria . . . . . . . . . . 76
4.2.1 Methane Metabolism Pathways in Methane-Oxidizing
Bacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
4.2.2 Preparation of Biocatalysts for the Production
of Methanol from Methane . . . . . . . . . . . . . . . . . . . . . . . . 84
4.2.3 Production of Methanol Using Methane-Oxidizing
Bacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
4.3 Comparison of the Methanol Productivity of Biocatalysts
and Heterogeneous Catalysts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
5 C–C Bond Formation via the Condensation of Methane
in the Presence or Absence of Oxygen . . . . . . . . . . . . . . . . . . . . . . . 103
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
5.2 Oxidative Coupling of Methane . . . . . . . . . . . . . . . . . . . . . . . . . . 104
5.3 Classification of Catalysts for the Oxidative Coupling
of Methane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
5.4 Role of Oxygen Species in Methyl Radical Formation
Over Various Metal Oxide Catalysts . . . . . . . . . . . . . . . . . . . . . . 106
5.4.1 Evidence of Methyl Radical Formation During OCM . . . . 106
5.4.2 O
− Oxygen Species for Methyl Radical Formation . . . . . . 106
5.4.3 Peroxide O 2
2− Ions: Metal Peroxides as Catalysts . . . . . . . 107
5.4.4 Superoxide Ion (O 2
− ) Species . . . . . . . . . . . . . . . . . . . . . 108
5.4.5 Various Oxygen Species for the Formation of Methyl
Radicals on the Catalyst Surface . . . . . . . . . . . . . . . . . . . . 108
5.4.6 Oxygen Ion Species in Catalysts . . . . . . . . . . . . . . . . . . . . 109
5.5 Reaction Network in the Oxidative Coupling of Methane . . . . . . . 110
5.5.1 C 2 H 6 and CO x as Primary Products . . . . . . . . . . . . . . . . . 110
5.5.2 Estimation of the First-Order Rate Constant
of Each Reaction Path . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
5.6 Relationship Between the Conversion of Methane
and the Selectivity Towards C 2
+ Hydrocarbons . . . . . . . . . . . . . . 113
5.7 Membrane Reactor for OCM . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Contents
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Derivatives from Methane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
3.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
4 Application of Biocatalysts for the Production of Methanol
from Methane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
4.2 Methane Metabolism in Methane-Oxidizing Bacteria . . . . . . . . . . 76
4.2.1 Methane Metabolism Pathways in Methane-Oxidizing
Bacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
4.2.2 Preparation of Biocatalysts for the Production
of Methanol from Methane . . . . . . . . . . . . . . . . . . . . . . . . 84
4.2.3 Production of Methanol Using Methane-Oxidizing
Bacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
4.3 Comparison of the Methanol Productivity of Biocatalysts
and Heterogeneous Catalysts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
5 C–C Bond Formation via the Condensation of Methane
in the Presence or Absence of Oxygen . . . . . . . . . . . . . . . . . . . . . . . 103
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
5.2 Oxidative Coupling of Methane . . . . . . . . . . . . . . . . . . . . . . . . . . 104
5.3 Classification of Catalysts for the Oxidative Coupling
of Methane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
5.4 Role of Oxygen Species in Methyl Radical Formation
Over Various Metal Oxide Catalysts . . . . . . . . . . . . . . . . . . . . . . 106
5.4.1 Evidence of Methyl Radical Formation During OCM . . . . 106
5.4.2 O
− Oxygen Species for Methyl Radical Formation . . . . . . 106
5.4.3 Peroxide O 2
2− Ions: Metal Peroxides as Catalysts . . . . . . . 107
5.4.4 Superoxide Ion (O 2
− ) Species . . . . . . . . . . . . . . . . . . . . . 108
5.4.5 Various Oxygen Species for the Formation of Methyl
Radicals on the Catalyst Surface . . . . . . . . . . . . . . . . . . . . 108
5.4.6 Oxygen Ion Species in Catalysts . . . . . . . . . . . . . . . . . . . . 109
5.5 Reaction Network in the Oxidative Coupling of Methane . . . . . . . 110
5.5.1 C 2 H 6 and CO x as Primary Products . . . . . . . . . . . . . . . . . 110
5.5.2 Estimation of the First-Order Rate Constant
of Each Reaction Path . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
5.6 Relationship Between the Conversion of Methane
and the Selectivity Towards C 2
+ Hydrocarbons . . . . . . . . . . . . . . 113
5.7 Membrane Reactor for OCM . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Contents
ix