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Titania crystal phases were able to tune the nature of metal through metal–support interaction and acidic sites for surface rearrangement and hydrogenation of furfural.

Copper nanoparticles dispersed on amine functionalised mesoporous silica SBA-15 (Cu/NH2-SBA-15) were synthesised by a simple sol–gel and impregnation method using sodium borohydride (NaBH4) as a reducing agent. The morphology, mesostructure and functionality of the ordered mesoporous Cu/NH2-SBA-15 were evaluated by powder X-ray diffraction (PXRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Nitrogen adsorption–desorption isotherms (BET) and Fourier transform infrared spectroscopy (FTIR). The results obtained revealed, that the amine functionalised SBA-15 holds hexagonal lamelliform with surface area and pore size of 250 m2/g, 2.2 nm respectively. Moreover, these short vertical channels have a substantial role in the uniform dispersion of copper nanoparticles within the meso-channels of amine functionalised SBA-15. Cu nanoparticles in the size range of 4–7 nm were dispersed on the NH2-SBA-15 support. To confirm the potential catalytic activity, Cu/NH2-SBA-15 was tested in Mannich reaction. The catalyst showed an excellent catalytic activity for the yield (90%) of β-amino carbonyl compounds that serve as a building block for the synthesis of lactams, peptides, amino alcohols and precursor for various amino acids. Further, the activity of the catalyst was also tested for the reduction of dyes. The structural influence over the reduction pathways was studied on triphenyl methane dyes.

Activated carbon from agro waste groundnut (Arachis hypogaea) shell was prepared by chemical activation and used as support for dispersion of 5% platinum nanoparticles. The Pt nanoparticles were obtained by the reduction in hydrogen gas medium. The synthesized groundnut activated carbon/platinum catalyst was characterized by various techniques such as X-ray powder diffraction, electron microscopies and X-ray photoelectron spectroscopy. The catalytic behaviour of the synthesized catalyst was investigated by exploring it as catalyst for the reduction of various classes of dyes; namely, triphenylmethane dyes such as malachite green, phenol red and bromophenol blue, xanthene dyes: rose bengal, rhodamine 6 G, rhodamine B, thiazine dye: methyelene blue, azo dye: congo red and 4-nitrophenol by sodium borohydride in aqueous medium. Under suitable reaction conditions, for all tested dyes, cationic dyes were reduced at a faster rate than anionic dyes. The rate of reduction on the structure of dye and nature of catalyst was employed.

Uniform-spherical Pd nanoparticles (NPs) supported catalysts were prepared by a mild-temperature chemical reduction method. Pd colloidal suspension was wet-impregnated on various supports, P25-TiO2, SiO2, and γ-Al2O3. In XPS, asymmetric Pd 3d5/2 peak reveals % surface concentration of Pd2+ and Pd0 species. The surface Pd2+/Pd0 ratio on the catalyst surface varied between ~1 to 0.15 depending on strong-metal support interactions (SMSI) inferred from XPS and H2-TPR studies. A linear correlation between Pd2+/Pd0 ratio and turnover frequency (TOF) was observed, with 1% Pd/P25-TiO2 showing the highest TOF/selectivity with Pd2+/Pd0 ratio ~1.0, whereas 1% Pd/γ-Al2O3 showed the lowest TOF/selectivity with lowest Pd2+/Pd0 ratio 0.15. Interestingly, H2-TPR reveals PdH decomposition peaks along with the Ti4+ reduction peak, and XPS Ti 2p of 1% Pd/P25-TiO2 indicates the presence of Ti3+ in TiO2 lattice, which may have generated due to H2-spillover from Pd to P25-TiO2. Hence, we observed excellent COL selectivity (~90%) and 100 % conversion with 1.5% Pd/P25-TiO2 catalyst. Excellent COL selectivity may be ascribed to small Pd NPs (~3 nm) with intrinsic surface electropositive sites (Pd2+) created by partial reduction on the catalyst surface along with SMSI. These electropositive sites (Pd2+) promote preferential C=O adsorption. On the other hand, post-reduced catalyst in H2 @300 °C (1% Pd/P25-TiO2-PRH2) with large Pd NPs (~7 nm) showed significant selectivity loss (>50 %), which confirm significance of small Pd NPs with electropositive sites.

Electrochemical devices for energy storage play a crucial role in the energy dependent world for meeting the situation of fast depletion of fossil fuels. Among various possible electrochemical energy storage devices, supercapacitors have been attracting interest in both academic community and industrial production in the past few decades due to their desirable power density, fast charge/discharge rates, and favorable life cycles. Supercapacitors and rechargeable batteries are similar devices with negative electrodes, positive electrodes, and separators that are present with an electrolyte. Normally, supercapacitors can be considered as the intermediate between the conventional battery and dielectric capacitor. In these days, supercapacitors are employed in many applications, such as consumer electronics, possibly in transportation, grid balancing, and power back up replacing the use of batteries in these applications. Supercapacitors can also be used along with rechargeable batteries in order to provide additional power that is normally required in these applications.

Direct methanol fuel cell may become a practical device sooner or later. For effective utilization of this device for energy conversion the anode reaction has to be promoted efficiently and economically. Among the various anode catalysts tried, Pt-based systems have shown some promise and Pt in combination with other metals are examined in order to overcome the poisoning effect of partially oxidized product, such as Co or –CHO species. The limitations in this technology, namely, carbon corrosion, Ru dissolution, and crossover, in addition to methanol crossover, have to be overcome to make this a commercially viable technology. The prospects of this technology are also outlined.

Herein, the fluorescent carbon dots (CDs) with blue emission were prepared by hydrothermal treatment using pineapple peel as a source of carbon. The as-prepared CDs exhibited turn-Off fluorescence behavior toward Hg2+ and subsequent turn-On behavior for l-cysteine along with enhanced biocompatibility and negligible cytotoxicity for cell imaging. The practical applicability of carbon dots was used for the quantification of Hg2+ in water. On the basis of the spectral characteristic changes, we have designed individual elementary logic operations such as NOT and IMP gates, by utilizing CD as probe and Hg2+ and l-Cys as chemical inputs. We have also demonstrated the utility of this system in electronic security devices and as memory element, with the idea of the switching.

Hierarchical mesoporous TiO2 was synthesized via a solvothermal technique. The sonochemical method was adopted to decorate plasmonic nanoparticles (NPs) (Ag, Au) on the pores of mesoporous TiO2. The crystallinity, structure, and morphology were determined to understand the physicochemical nature of the nanocomposites. The catalytic efficiency of the plasmonic nanocatalysts was tested for the azo dyes (congo red, methyl orange, acid orange 10, and remazol red) under solar and visible light irradiations. The generation of hydroxyl radicals was also studied using terephthalic acid as a probe molecule. An attempt was made to understand the influence of size, work function and Fermi level of the metal NPs toward the efficiency of the photocatalyst. The efficiency of the nanocomposites was found to be in the order of P25 < mesoporous TiO2 < mesoporous Ag–TiO2 < mesoporous Au–TiO2 nanospheres under both direct solar light and visible light irradiation. The results indicated that the adsorption of dye, anatase ph...

Sodium tantalate (NaTaO3), a typical mixed metal oxide with orthorhombic structure, has been modified by incorporation of lanthana (LaxNa(1 − x)TaO(3 + y) or LNTO), followed by doping/co-doping with N and Fe3+, with the objective of improving visible light absorption and photo physical properties. XRD and XPS results reveal that La3+ occupies Na+ ion sites, Fe3+ ions Ta5+ ion sites and N the O2− ion sites, possibly as N3− in the tantalate matrix. Incorporation of the dopants in the tantalate matrix has been confirmed by SEM-EDXA and STEM-EDS elemental mapping and surface composition analysis by XPS. Fe and N co-doping in tantalate matrix results in the narrowing of the band gap due to the creation of additional energy levels within the band gap and consequently, visible light absorption. Presence of Fe3+ and La3+ dopants in the tantalate lattice ensures electro-neutrality. Efficient charge trapping and de-trapping by Fe3+ and Fe4+ ions reduce the probability of charge carrier recombination as revealed by photo luminescence spectroscopy and further promote charge migration and interfacial charge transfer. The catalysts display significant activity for photo catalytic reduction of carbon dioxide (PCRC) in aqueous alkaline medium, with methanol as major product. Synergetic effect due to co-doping of LNTO with Fe and N improves visible light absorption, retards recombination of charge carriers and thus helps to enhance PCRC activity by nearly three times vis-a-vis pristine NaTaO3.

“Synthesis of nitrogen-doped carbon nanotubes from polymeric precursors (polystyrene and polypyrrole) by poly-condensation followed by carbonization under an inert atmosphere is reported. Three different carbonization temperatures (500 °C, 700 °C and 900 °C) were employed to synthesize three different carbon nanostructures with different morphologies. These were designated as NCNR-500 (nitrogen-doped carbon nanorods), NCBCT-700 (nitrogen-doped fused bead carbon nanotubes), and NCNT-900 (nitrogen-doped carbon nanotubes) according to morphology and carbonization temperature. Microstructure, morphology, porosity, and nitrogen content were characterized by several different techniques. The effects of carbonization temperature and the role of functional groups were also investigated. Total and excess hydrogen storage capacities of 2.0 wt% and 1.8 wt%, respectively, were measured at 298 K and 100 bar for the NCNT-900 material. This is higher than the capacities of the NCNR-500 and NCBCT-700 materials. NCNT-900 exhibited a porous structure with high specific surface area and total pore volume of 870 m/g and 0.62 cm3/g, respectively.

Strontium titanates, SrTiO3, Sr3Ti2O7 and Sr4Ti3O10, with perovskite structure, have been modified by co-doping with N, S and Fe and characterized by X-ray diffraction (XRD), Diffuse reflectance Spectroscopy (DRS), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDXA), X-ray Photoelectron Spectroscopy (XPS) and Photo Luminescence Spectroscopy (PLS) techniques. XRD, EDXA and XPS results substantiate the incorporation of the three dopants into the titanate matrices. Based on the XPS binding energy data, it is inferred that doped nitrogen in SrTiO3 and Sr4Ti3O10 phases occupies O2− ion sites by substitution and interstitial sites in Sr3Ti2O7. Fe as Fe3+ and S as cationic S6+ occupy Ti4+ ion sites in the respective lattice in all three titanates. Additional energy levels created by the dopants within the band gap result in narrowing of the band gap, as revealed by DRS data and thus enable visible light absorption by the modified titanates. Significant reduction in the intensity of photo luminescence emission lines of modified titanates indicates that doping retards the recombination rates of charge carriers, enhancing their life time. Changes in the photo-physical properties brought out by modification with dopants improve the activity for photo catalytic reduction of CO2 vis-a-vis pristine titanates. Both Sr3Ti2O7 and Sr4Ti3O10, perovskites with layered structure, display higher activity when compared to simple perovskite, SrTiO3. Layered structure facilitates faster transport of charge carriers and the interlayer space could function as oxidation/reduction reaction sites, leading to the separation of charge carriers. Amongst the two layered perovskites, double layered Sr3Ti2O7 displays higher activity compared to triple layered Sr4Ti3O10 since the conduction band minimum of Sr3Ti2O7 is at higher negative energy level vis-a-vis that for Sr4Ti3O10 and the inter layer spacing is appropriate for CO2 reduction and splitting of water as well.

Carbon dots (CDs) with 48% quantum yield (QY) were synthesized by simple hydrothermal treatment using Pseudo-stem of banana plant as carbon source. As synthesized CDs were characterized using UV–vis, fluorescence, dynamic light scattering (DLS), Fourier transform infrared (FT-IR), Raman, X-ray photoelectron spectroscopy (XPS) and High resolution transmission electron microscopic (HRTEM) techniques. A fluorescent nanosensor which exhibits highly specific recognition capability towards Fe 3+ over other competing metal ions has been reported. CD exhibits fluorescent “turn-off” sensing nature with high selectivity towards Fe 3+ with a detection limit as low as 6.4 nM and “turn-on” property towards S 2 O 3 2− anion. The biocompatibility of CDs was revealed from the cytotoxicity studies on cancerous cells (HeLa, MCF-7 (Michigan Cancer Foundation-7)) and was employed as fluorescent probes for multi-coloured (blue, green and red) imaging of HeLa and MCF-7 cells. Due to the bright fluorescence, water solubility, high photo-stability, low toxicity, cell-membrane permeability and good biocompatibility, as-prepared carbon nanodots are demonstrated to be excellent probe as bio-imaging agent.

Metal cluster, at sub-nanometer level has a unique property in the activation of small molecules, in contrast to that of bulk surface. In the present work, singly exposed active site of copper metal cluster at sub-nanometer level was designed to arrive at the energy minimised configurations, binding energy, electrostatic potential map, frontier molecular orbitals and partial density of states. The ab initio molecular dynamics was carried out to probe the catalytic nature of the cluster. Further, the stability of the metal cluster and its catalytic activity in the electrochemical reduction of CO 2 to CO were evaluated by means of computational hydrogen electrode via calculation of the free energy profile using DFT/B3LYP level of theory in vacuum. The activity of the cluster is ascertained from the fact that the copper atom, present in a two coordinative environment, performs a more selective conversion of CO 2 to CO at an applied potential of −0.35 V which is comparatively lower than that of higher coordinative sites. The present study helps to design any sub-nano level metal catalyst for electrochemical reduction of CO2 to various value added chemicals.

Mesoporous carbon nitrides (MCNs) with large surface areas and uniform pore diameters are unique semiconducting materials and exhibit highly versatile structural and excellent physicochemical properties, which promote their application in diverse fields such as metal free catalysis, photocatalytic water splitting, energy storage and conversion, gas adsorption, separation, and even sensing. These fascinating MCN materials can be obtained through the polymerization of different aromatic and/or aliphatic carbons and high nitrogen containing molecular precursors via hard and/or soft templating approaches. One of the unique characteristics of these materials is that they exhibit both semiconducting and basic properties, which make them excellent platforms for the photoelectrochemical conversion and sensing of molecules such as CO2, and the selective sensing of toxic organic acids. The semiconducting features of these materials are finely controlled by varying the nitrogen content or local electronic structure of the MCNs. The incorporation of different functionalities including metal nanoparticles or organic molecules is further achieved in various ways to develop new electronic, semiconducting, catalytic, and energy harvesting materials. Dual functionalities including acidic and basic groups are also introduced in the wall structure of MCNs through simple UV-light irradiation, which offers enzyme-like properties in a single MCN system. In this review article, we summarize and highlight the existing literature covering every aspect of MCNs including their templating synthesis, modification and functionalization, and potential applications of these MCN materials with an overview of the key and relevant results. A special emphasis is given on the catalytic applications of MCNs including hydrogenation, oxidation, photocatalysis, and CO2 activation. Refereed/Peer-reviewed

The nitrogen doped graphene was synthesized by hydrothermal route utilizing 2-Chloroethylamine hydrochloride as nitrogen precursor in the presence of graphene oxide (GO). Nitrogen-doped graphene material is developed for its application in hydrogen storage at room temperature. Nitrogen doped graphene layered material shows ~1.5 wt% hydrogen storage capacity achieved at room temperature and 90 bar pressure.

Photoelectrochemical water splitting has been frontier research in the last 50 years to meet the energy demand from sustainable hydrogen production. Various materials have designed and engineered to split the water to the constituents. However, the efforts in this regard do not lead the process to a viable scale. The chapter deals with the perspective on the current scenario of material designing approach and its consequences. Also, a revisit to the genesis of the photoelectrochemical water splitting in the boom years and cited the essential articles in the field appeared before 1990 in the form of a chronological table. A prospect for the future of the field has been suggested based on the effect of the photon as well as electric field together in the system—also, a proposition on the materials design aspects given.

Here in we report a facile method of self-phosphorous doped porous carbon by a simple carbonization route (without using any activation process) under argon gas atmosphere. The as-prepared material with high surface area of 756 m2 g−1 shown high H2 storage capacity of ∼1.75 wt% at 298 K and 100 bars. Also, it exhibited a high specific capacitance of 253 Fg−1 at the current density of 1 A g−1. Further, it also showed the capacitive retention of ∼95% at the current density of 5 A g−1 for 10,000 cycles. Interestingly, a carbon material with porous structure is predominantly inspiring as they are cost-effective and ease to synthesis for industrial applications. Biomass derived self-phosphorous doped porous carbon is considered as a superior material for supercapacitor and hydrogen storage applications. It is shown high performance for both the applications, due to its exceptional chemical stability, conductivity, micro-meso porosity, high specific surface area, cost-effectiveness and sustainability.

Carbon sequestration is a new technology that is gaining importance in combating the harmful effects of global warming. The potential for carbon sequestration from domestic sewage treatment plants operating in India was studied. Based on the data provided by the Government of India on the generation of domestic sewage by State, the organic load generation, sequestration potential and net release of CO2 were calculated. By going in for carbon sequestration, domestic sewage treatment in India has a potential to be a carbon neutral sector with a capacity to store 22 thousand tonnes of CO2 every day at current levels. The Government of India's focus is on increasing the share of renewable energy sources to combat emissions; however, carbon sequestration technology would be an ideal solution for deployment over the time period required for renewable energy' share to become significant. Three metro cities, viz., Delhi, Mumbai, and Chennai are immediate prospects that could adopt this technology, followed by other cities. The prevalent Renewable Energy Credit Trading Scheme in India can support carbon sequestration technology infusion. © 2016 American Institute of Chemical Engineers Environ Prog, 2016

Lanthanum modified sodium tantalate, Na (1−x) La x TaO (3+x) , in conjunction with cobalt (II) tetra phenyl porphyrin (CoTPP) as sensitizer, has been explored for photo catalytic reduction of carbon dioxide (PCRC) with water. HOMO and LUMO energy level characteristics/redox potentials for ground (S 0 ) and excited states (S 1 singlet) of CoTPP have been calculated by Density Functional Theory (DFT). HOMO and LUMO energy levels enable sensitization of the tantalate, a typical wide band gap semi-conductor, with visible light. Visible light absorption by CoTPP results in the direct transfer of photo generated electrons to the conduction band of the tantalate, in addition to the intrinsic UV light excitation. Besides, sensitization also retards charge carrier recombination rate, as indicated by the photo luminescence spectral data for the pristine and sensitized Na (1−x) La x TaO (3+x) . A co-operative effect of these factors contributes towards nearly 3 fold increase in apparent quantum yield value for PCRC with the 1% w/w CoTPP/tantalate composite vis-a-vis pristine tantalate. After 20 h of irradiation, rate of methanol formation remains constant with pristine and sensitized tantalates, while the rate of formation of ethanol increases on sensitization, indicating multi electron reduction process. Chemical composition and structural characteristics of the composite are preserved even after 20 h of irradiation.

Lanthanum doped sodium tantalate (Na(1−x)LaxTaO(3+x)) with Pt, Ag, Au, CuO, NiO and RuO2 as co-catalysts, have been prepared and characterized by XRD, DRS, photoluminescence spectroscopy, SEM and TEM. Photocatalytic reduction of CO2 on these catalysts in alkaline medium under UV–Visible radiation yields methanol and ethanol as major products with traces of methane, ethane, ethylene, etc. Maximum apparent quantum yield (AQY) for CO2 reduction is achieved on the formulation with 0.2 wt% NiO, followed by 1 wt% CuO as co-catalysts. DRS studies reveal that the addition of co-catalysts brings about reduction in band gap energy of NaTaO3 and its light absorption onset edge is extended into the visible region. Coupling of the conduction band bottom energy levels of NiO and CuO with that of Na(1−x)LaxTaO(3+x) shows that they facilitate easy transfer of photo-generated electrons from the doped tantalate to NiO/CuO, wherein these electrons participate in simultaneous hydrogen generation by water splitting and CO2 photoreduction processes. Other co-catalysts, like, Pt, Ag, Au and RuO2 act as electron traps, resulting in charge separation, which, in turn, leads to improvement in photo-catalytic activity. Besides, significant reduction in the intensity of photoluminescence lines observed for Na(1−x)LaxTaO(3+x) with different co-catalysts also indicates longer life time of the charge carriers. Used catalysts retain the cubic perovskite structure of the fresh catalyst during the reaction for 20 h and stable activity is displayed for three cycles. The alkaline medium plays multiple roles, acting as scavenger of holes, increasing the solubility of CO2 and stabilization of NiO. NaTaO3 based catalysts could become viable alternatives to titania for this application.

Bimetallic catalysts of the type Ni–M with M = Cu, Ag and Au, and supported on TiO2-P-25 have been prepared by chemical reduction using glucose as the reducing agent. Hydrogenation of cinnamaldehyde (CAL) to yield hydrocinnamaldehyde (HCAL), cinnamyl alcohol (COL) and hydrocinnamyl alcohol (HCOL) has been studied on the catalysts in the temperature range 60–140 °C and at 20 kg/cm2 pressure, with methanol as solvent. Ni crystallite sizes, measured by X-ray line broadening analysis (XLBA), H2 pulse chemisorption and Transmission Electron Microscope (TEM) techniques, are in the range 8–12 nm. Temperature Programmed Reduction (TPR) and Diffuse Reflectance Spectroscopic (DRS) studies indicate the formation of Ni–Cu alloys, while Ni–Ag and Ni–Au exist as bimetallic nanoparticles. High-resolution HRTEM studies show that the bimetallic nanoparticles are in close contact, forming hetero junctions. Changes in the XPS binding energy values for Ni 2p1/2 and Ni 2p3/2 levels reveal that Cu/Ag/Au, tend to increase electron density around Ni, which retards the adsorption of CAL via olefinic bond and weakens Ni H bond strength. H2 TPD measurements also indicated weakening of Ni H bond. Bimetallic catalysts display higher CAL conversion and selectivity to COL vis-a-vis the corresponding monometallic catalysts at lower reaction temperatures, 60–80 °C. But, selectivity to COL decreases at higher temperatures, 100–120 °C. Mode of adsorption of CAL and nature of adsorbed hydrogen on bimetallic catalysts influence their activity and selectivity.

Hydrogen storage capacity of boron substituted carbon materials synthesized by the carbonization of resorcinol and triethylborate as carbon and boron sources respectively is reported. The effects of the boron-doping and carbonization temperature and the role of functional groups have been investigated. The hydrogen adsorption capacity has been studied with a high pressure volumetric analyzer (HPVA) and a maximum of 5.9 wt% hydrogen storage capacity was observed at 298 K and 100 bar pressure. At 77 K in both carbon samples (namely BC-600 or BC-800) show only fractional weight percent of hydrogen sorption (1.1 and 0.5 wt%). The nearly 5 weight % hydrogen storage was obtained by loading heteroatom (B) to carbon sample at 298 K and 100 bar.

Developing new efficient catalysts for the electrochemical reduction of carbon dioxide to formic acid is important in the process of mitigating environmental CO2. In the present work, we have designed metal (M) clusters anchored on a polyaniline (PANI) conducting polymer electrode (M@PANI), where, M = Ni, Pd, Pt, Cu, Ag & Au, and evaluated their potential catalytic activity towards CO2 reduction by means of computational hydrogen electrode using hybrid density functional theory methods. The predicted binding energy and electronic properties of M@PANI suggest a thermodynamically feasible reaction which retains its conducting property with enhancement. The modified electrodes favour the formation of HCOOH involving H*COO species via the formate pathway. The computed limiting potentials suggest that Cu@PANI is a suitable electrode material for the CO2 reduction reaction leading to HCOOH.

A variety of distinctive techniques have been developed to produce graphene sheets and their functionalized subsidiaries or composites. The production of graphene sheets by oxidative exfoliation of graphite can be a suitable route for the preparation of high volumes of graphene derivatives. P-substituted graphene material is developed for its application in hydrogen sorption in room temperature. Phosphorous doped graphene material with multi-layers of graphene shows a nearly ~2.2 wt% hydrogen sorption capacity at 298 K and 100 bar. This value is higher than that for reduced graphene oxide (RGO without phosphorous).

The photoelectrochemical (PE) reduction of carbon dioxide is an emerging area of research. Various electrode combinations have been employed for the construction of PE cells. Various types of semiconductors, elemental semiconductors, oxides, electrodes decorated with molecular cocatalysts, or metals have been employed for the reduction of carbon dioxide. This chapter also deals with the challenges and prospects of this area of research.

This chapter deals with the prospective aspects and future possibilities of carbon dioxide reduction. The short-term and long-term goals are pointed out. The aspects on which further information is required are explicitly stated.

In this chapter, the modes of activation of carbon dioxide on surfaces and the geometric arrangements of the adsorbed carbon dioxide are discussed. The bonding scheme within carbon dioxide and the nature of (Physisorption and Chemisorption) adsorption of carbon dioxide on surfaces have been considered. The adsorption and dissociation of CO 2 on the alkali metal activated on metal surfaces have been outlined. The challenge is to design catalysts that can provide ways in which CO 2 can be utilized as a C 1 feedstock for the production of valuable fuels and chemicals.