In the present paper a techno-economic hydrogen production and transportation costs to export from Colombia to Europe and Asia were determined using the open-source Python tools, such as ...WindPowerLIB, PVLIB, ERA5 weather data, and the Hydrogen-2-Central (H2C) model. Calculations were performed as well for Chile, for comparison as a regional competitor. In addition, a detailed overview of Colombia's energy system and national efforts for a market ramp-up of renewable energy and hydrogen is provided. The application of the model in different scenarios shows Colombia's potential to produce green hydrogen using renewable energies. The prices estimated are 1.5 and 1.02 USD/kgH2 for 2030 and 2050 with wind power, and 3.24 and 1.65 USD/kgH2 for 2030 and 2050 using solar energy. Colombia can become one of the most promising hydrogen suppliers to Asian and European countries with one of the lowest prices in the production and transportation of green hydrogen.
Display omitted
•Open-source models were used to obtain costs of H2 production and transportation.•LCOH of green H2 using wind energy is 1.63 and 1.11 USD/kgH2 by 2030 and 2050.•LCOH of green H2 using solar energy is 3.72 and 1.89 USD/kgH2 by 2030 and 2050.•Exporting H2 to Asia by 2030 and 2050 costs 3.47 and 2.9 USD/kg, respectively.•Exporting H2 to Europe by 2030 and 2050 costs 3.1 and 2.55 USD/kg, respectively.
On-board and off-board performance and cost of cryo-compressed hydrogen storage are assessed and compared to the targets for automotive applications. The on-board performance of the system and ...high-volume manufacturing cost were determined for liquid hydrogen refueling with a single-flow nozzle and a pump that delivers liquid H
2 to the insulated cryogenic tank capable of being pressurized to 272
atm. The off-board performance and cost of delivering liquid hydrogen were determined for two scenarios in which hydrogen is produced by central steam methane reforming (SMR) or by central electrolysis. The main conclusions are that the cryo-compressed storage system has the potential of meeting the ultimate target for system gravimetric capacity, mid-term target for system volumetric capacity, and the target for hydrogen loss during dormancy under certain conditions of minimum daily driving. However, the high-volume manufacturing cost and the fuel cost for the SMR hydrogen production scenario are, respectively, 2–4 and 1.6–2.4 times the current targets, and the well-to-tank efficiency is well short of the 60% target specified for off-board regenerable materials.
Hydrogen generation via electrochemical splitting plays an important role to achieve hydrogen economy. However, the large‐scale application is highly limited by high cost and low efficiency. Herein, ...a new type of rechargeable Zn–hydrazine (Zn–Hz) battery is proposed and realized by a bifunctional electrocatalyst based on two separate cathodic reactions of hydrogen evolution (discharge: 2H2O + 2e− → H2 + 2OH−) and hydrazine oxidation (charge: 1/2 N2H4+2OH−→1/2 N2+2H2O+2e−$1{\rm{/}}2\,{{\rm{N}}_2}{{\rm{H}}_4}{\bm{ + }}2{\rm{O}}{{\rm{H}}^{\bm{ - }}}{\bm{ \to }}1{\rm{/}}2\,{{\rm{N}}_2}{\bm{ + }}2{{\rm{H}}_2}{\rm{O}}{\bm{ + }}2{e^{\bm{ - }}}$). This Zn–Hz battery, driven by temporally decoupled electrochemical hydrazine splitting on the cathode during discharge and charge processes, can generate separated hydrogen without purification. When the highly active bifunctional cathode of 3D Mo2C/Ni@C/CS is paired with Zn foil, the Zn–Hz battery can achieve efficient hydrogen generation with a low energy input of less than 0.4 V (77.2 kJ mol−1) and high energy efficiency of 96%. Remarkably, this battery exhibits outstanding long‐term stability for 600 cycles (200 h), achieving continuous hydrogen production on demand, which presents great potential for practical application.
A new type of rechargeable Zn–hydrazine battery is proposed for separate and efficient hydrogen generation by temporally decoupled hydrazine splitting. The battery, realized by a bifunctional electrocatalyst, decouples the electrocatalytic hydrogen evolution (2H2O + 2e− → H2 + 2OH−) and hydrazine oxidation (1/2 N2H4+2OH−→1/2 N2+2H2O+2e−)\(1{\rm{/}}2\,{{\rm{N}}_2}{{\rm{H}}_4} + 2{\rm{O}}{{\rm{H}}^ - } \to 1{\rm{/}}2\,{{\rm{N}}_2} + 2{{\rm{H}}_2}{\rm{O}} + 2{e^ - })\, which achieves separate hydrogen generation, ansimultaneously efficient hydrogen production with low energy input of less than 0.4 V and ultrahigh energy efficiency of 96%.
It is an urgent requirement to develop non-precious metal-based catalysts with excellent electrocatalytic activity and stability to accelerate the development of hydrogen generation via ...energy-efficient routes. Herein, a facile and scalable strategy was developed to synthesize both rod-like Co(OH)F and Co–P nanoarrays supported on Ni-foam, denoted as Co(OH)F/NF and Co–P/NF, respectively. Electrochemical measurements demonstrate that Co–P/NF exhibits excellent electrocatalytic performance for the hydrogen evolution reaction (HER), delivering a low overpotential of 70 mV and 43 mV at 10 mA cm −2 in alkaline and acid media, respectively. Furthermore, the as-prepared Co(OH)F/NF contributes to an outstanding oxygen evolution reaction (OER) performance with a low oxidation potential of about 1.5 V at 10 mA cm −2 . In addition, the Co(OH)F/NF also can enable highly efficient urea oxidation reaction (UOR) electrocatalysis, which can be utilized to substitute OER to lower the overpotential and thus reduce electrical energy consumption during H 2 -production. As a proof of concept, full water-splitting measurements were performed with Co–P/NF and Co(OH)F/NF as cathode and anode, respectively, in 1 M KOH with 0.7 M urea. The Co–P/NF‖Co(OH)F/NF electrode is capable of producing a current density of 20 mA cm −2 at a cell potential of only 1.42 V, which is 230 mV less than that for the urea-free counterpart, demonstrating its potential feasibility in practical applications of energy-efficient hydrogen production.
Boronic acids and their derivatives are some of the most useful reagents in the chemical sciences
, with applications spanning pharmaceuticals, agrochemicals and functional materials. Catalytic C-H ...borylation is a powerful method for introducing these and other boron groups into organic molecules because it can be used to directly functionalize C-H bonds of feedstock chemicals without the need for substrate pre-activation
. These reactions have traditionally relied on precious-metal catalysts for C-H bond cleavage and, as a result, display high selectivity for borylation of aromatic C(sp
)-H bonds over aliphatic C(sp
)-H bonds
. Here we report a mechanistically distinct, metal-free borylation using hydrogen atom transfer catalysis
, in which homolytic cleavage of C(sp
)-H bonds produces alkyl radicals that are borylated by direct reaction with a diboron reagent. The reaction proceeds by violet-light photoinduced electron transfer between an N-alkoxyphthalimide-based oxidant and a chloride hydrogen atom transfer catalyst. Unusually, stronger methyl C-H bonds are borylated preferentially over weaker secondary, tertiary and even benzylic C-H bonds. Mechanistic studies indicate that the high methyl selectivity is a result of the formation of a chlorine radical-boron 'ate' complex that selectively cleaves sterically unhindered C-H bonds. By using a photoinduced hydrogen atom transfer strategy, this metal-free C(sp
)-H borylation enables unreactive alkanes to be transformed into valuable organoboron reagents under mild conditions and with selectivities that contrast with those of established metal-catalysed protocols.
The goal of this study is to define and assess an off-grid hybrid renewable energy with hydrogen storage system. The system combines solar and wind energy, hydrogen production unit and fuel cell. ...This photovoltaic/wind hydrogen energy system focuses on a large scale system with constant electrical load and especially suitable for remote area applications. Energy, exergy and economic analysis are conducted for this system. The pattern of the produced power for the photovoltaic (PV) system and wind turbine with a dynamic model of solar and wind energy are determined. Also, components sizing of the proposed system is determined. Energy and exergy analysis of the PV system was reported the average of 12% and 16% for energy and exergy efficiencies, respectively. The average energy and exergy efficiencies of the wind turbine were obtained approximately 32% and 25%, respectively. The maximum exergy destruction for the PV system was obtained around 65%. Also, based on economic analysis, energy storage system was included 50% of the total investment.
•Design an off-grid hybrid renewable energy with hydrogen storage system.•The system was proposed for remote area applications in the south of Iran.•Energy and exergy efficiencies for the PVS were obtained 12 and 16%, respectively.•For the wind turbine, 32% energy efficiency and 26% exergy efficiency was obtained.•The payback period for the system was obtained approximately 11 years.
Abstract
Hydrogen evolution reaction (HER) in neutral media is of great practical importance for sustainable hydrogen production, but generally suffers from low activities, the cause of which has ...been a puzzle yet to be solved. Herein, by investigating the synergy between Ru single atoms (RuNC) and RuSe
x
cluster compounds (RuSe
x
) for HER using ab initio molecular dynamics, operando X-ray absorption spectroscopy, and operando surface-enhanced infrared absorption spectroscopy, we establish that the interfacial water governs neutral HER. The rigid interfacial water layer in neutral media would inhibit the transport of H
2
O*/OH* at the electrode/electrolyte interface of RuNC, but the RuSe
x
can promote H
2
O*/OH* transport to increase the number of available H
2
O* on RuNC by disordering the interfacial water network. With the synergy of RuSe
x
and RuNC, the resulting neutral HER performance in terms of mass-specific activity is 6.7 times higher than that of 20 wt.% Pt/C at overpotential of 100 mV.
Hydrogenases are enzymes that catalyze the reversible conversion of protons to hydrogen gas, using earth-abundant metals such as nickel and/or iron. This characteristic makes them promising for ...sustainable energy applications, particularly in clean hydrogen production. However, their widespread use faces challenges, including a limited pH range and susceptibility to oxygen. In response to these issues, SacCoMyo is introduced as an artificial enzyme. SacCoMyo is designed by replacing the native metal in the myoglobin (Myo) scaffold with a hydroxocobalamin (Co) porphyrin core and complemented by a protective heteropolysaccharide-linked (Sac) shell. This engineered protein proves to be resilient, maintaining robust functionality even in acidic environments and preventing denaturation in a pH 1 electrolyte. The cobalt porphyrin core of SacCoMyo reduces the activation overpotential for hydrogen generation. A high turnover frequency of about 2400 H
2
s
−1
is demonstrated in the presence of molecular oxygen, showcasing its potential in biohydrogen production and its ability to overcome the limitations associated with natural hydrogenases.
SacCoMyo, an engineered artificial enzyme with a hydroxocobalamin core and protective heteropolysaccharide-linked shell, exhibits resilience in acidic electrolytes containing molecular oxygen, reducing the activation overpotential for hydrogen generation and demonstrating high turnover frequency.
The present study compared the mesophilic and thermophilic alkaline fermentation of waste activated sludge (WAS) for hydrogen production with focus on homoacetogenesis, which mediated the consumption ...of H2 and CO2 for acetate production. Batch experiments showed that hydrogen yield of WAS increased from 19.2 mL H2/gVSS at 37 °C and pH 10–80.1 mL H2/gVSS at 55 °C and pH 10. However, the production of volatile fatty acids (mainly acetate) was higher at 37 °C and pH 10 by comparison with 55 °C and pH 10. Hydrogen consumption due to homoacetogenesis was observed at 37 °C and pH 10 but not 55 °C and pH 10. Higher expression levels of genes relating with homoacetogenesis and lower expression levels of genes relating with hydrogen production were found at 37 °C and pH 10 compared to 55 °C and pH 10. The continuous experiment demonstrated the steady-state hydrogen yield of WAS was comparable to that obtained from batch experiments at 55 °C and pH 10, and homoacetogenesis was still inhibited. However, the steady-state hydrogen yield of WAS (6.5 mL H2/gVSS) was much lower than that (19.2 mL H2/gVSS) obtained from batch experiments at 37 °C and pH 10 due to the gradual enrichment of homoacetogens as demonstrated by qPCR analysis. The high-throughput sequencing analysis of 16S rRNA genes showed that the abundance of genus Clostridium, containing several homoacetogens, was 5 times higher at 37 °C and pH 10 than 55 °C and pH 10.
Display omitted
•Higher hydrogen yield was obtained at 55 °C and pH 10 compared to 37 °C and pH 10.•Higher production of VFAs was obtained at 37 °C and pH 10 compared to 55 °C and pH 10.•Long-term inhibition of homoacetogenesis was achieved at 55 °C and pH 10.•Homoacetogenesis occurred and homoacetogens were enriched at 37 °C and pH 10.
PDF
