A nitrate reduction method includes the step of reducing at least one type selected from a group of nitrates and nitrites at an active site included in a defect of graphene in a reduction reaction, wherein the graphene is a reduced product of graphene oxide, and the defect of the graphene is derived from a defect of the graphene oxide.

The present disclosure relates to a method of generating energy. This method involves providing a fuel cell comprising anode and cathode electrodes; a separator positioned between the anode and cathode electrodes; and anode and cathode catalysts. The anode catalyst comprises (i) a low-loading of platinum group metals (PGMs) supported on a Group 4-6 transition metal carbide (TMC) or nitride (TMN); (ii) an alloy or physical mixture comprising a Group 10 transition metal selected from Pt, Pd, and Ni and one or more of the following elements: Pt, Pd, Ni, Ir, Rh, Ru, Fe, Re, Sn, W, Mo, Ta, and Nb; or (iii) mixtures thereof. According to the method, a liquid anode fuel comprising one or more hydrazide compounds is added to the fuel cell to generate energy from the liquid anode fuel. Also disclosed is a fuel cell for generating energy from a liquid anode fuel comprising one or more hydrazide compounds.

Presented are fuel cell systems and control logic for extracting water from system exhaust, methods for making/using such systems, and electric-drive vehicles with aftertreatment systems for extracting water from fuel cell exhaust. An aftertreatment system for a fuel cell stack includes a condensate generator that fluidly connects to the fuel cell stack to receive exhaust output therefrom. The condensate generator includes an evaporator core with a refrigerant line that actively cool the exhaust via controlled circulation of refrigerant fluid. A condensate collector fluidly connected to the condensate generator includes a reservoir housing with a condensate trap that separates entrained water vapor from the cooled exhaust. The reservoir housing collects the separated water vapor as liquid water. A liquid storage container fluidly connected to the condensate collector receives and stores the collected water. An expansion valve regulates the amount of refrigerant fluid passed into the evaporator core through the refrigerant line.

A fuel cell system includes a fuel cell stack constituted by cells, each of the cells includes a fuel electrode, an air electrode, and an electrolyte, and generate electric power through a reaction of a fuel gas and air, a casing that houses the fuel cell stack, a temperature detector that detects a first temperature, the first temperature is a temperature of the fuel cell stack or inside the casing, and a controller. The controller controls based on the first temperature so as to allow an operation at a first predetermined temperature. The controller controls such that the first temperature reaches a temperature higher than or equal to a second predetermined temperature for a predetermined time. The second predetermined temperature is a temperature at which 475° C. embrittlement that occurs on stainless steel is eliminated. The first predetermined temperature is lower than the second predetermined temperature.

Stable solutions comprising high concentrations of charged coordination complexes, including iron hexacyanides are described, as are methods of preparing and using same in chemical energy storage systems, including flow battery systems. The use of these compositions allows energy storage densities at levels unavailable by other iron hexacyanide systems.

Various designs and configurations of and methods of operating fuel cell units, fuel cell systems and combined heat and power systems are provided that permit efficient thermal management of such units and systems to improve their operation.

A fuel cell is an ammonia fuel cell using an ammonia-containing fuel. A catalyst used for an anode of the fuel cell is a ruthenium complex having two first ligands and one second ligand, and the first ligand is pyridine or a condensed cyclic pyridine compound with or without a substituent, and the second ligand is 2,2′-bipyridyl-6,6′-dicarboxylic acid with or without a substituent on a pyridine ring.

An anion exchange ionomer is disclosed that contains a fluorinated, ether-free backbone, and a fluorinated ether based quaternary ammonium functional group. The novel polymer has improved chemical and mechanical stability as compared to the state-of-the-art materials for incorporation in anion exchange membrane. The disclosed anion exchange ionomer may be incorporated into an anion exchange membrane and used in electrochemical applications.

According to embodiments of the present disclosure, a solid oxide fuel cell includes a cathode, an anode, and a solid oxide electrolyte between the anode and the cathode. The solid oxide electrolyte includes a solid oxide, and the anode includes a porous scaffold. The porous scaffold includes a solid oxide having metal-based catalysts disposed on one or more surfaces of the porous scaffold. In embodiments, at least one ammonia decomposition layer is disposed proximate the surface of the porous scaffold and is configured to convert ammonia into hydrogen and nitrogen for subsequent feed of hydrogen to the anode. The ammonia decomposition layer also includes a metal decomposition catalyst.

According to embodiments of the present disclosure, a method of producing hydrogen in a fuel cell includes passing ammonia under pressure to an anode of the fuel cell, where the ammonia is decomposed into nitrogen gas and protons. The fuel cell comprises a cathode, the anode, and a proton-conducting electrolyte between the anode and the cathode. The anode includes an ammonia decomposition catalyst. The method further includes passing the purging the nitrogen from the anode, passing the protons through the proton-conducting electrolyte to the cathode, and passing the electrons from the anode to the cathode, wherein the protons and the electrons react to produce substantially pure hydrogen gas under pressure.