A process for preparing a catalytic material of an electrode for electrochemical reduction reactions, said material comprising an active phase based on at least one group VIB metal and an electrically conductive support, which process is carried out according to at least the following steps:

a) bringing water into contact with said electrically conductive support,
b) bringing said wet support into contact with at least one metallic acid hydrate comprising at least one group VIB metal, of which the melting point of said metallic acid hydrate is between 20° C. and 100° C., the weight ratio of said metallic acid to said electrically conductive support being between 0.1 and 4,
c) heating, with stirring, to a temperature between the melting point of said metallic acid hydrate and 100° C.,
d) carrying out a sulfurization step at a temperature of between 100° C. and 600° C.

The present invention relates to an MPC-based hierarchical coordinated control method and device for a wind-hydrogen coupling system. The method comprises the following steps: (1) dividing the wind-hydrogen coupling system into upper-layer grid-connected control and lower-layer electrolytic cell control; (2) controlling grid-connected power to track a wind power prediction curve by adopting an MPC control algorithm for upper-layer grid-connected control, and obtaining an electrolytic cell power control quantity for the lower-layer electrolytic cell control at the same time; (3) dividing operation states of electrolytic cell monomers into four operation states of rated power operation, fluctuating power operation, overload power operation and shutdown; and (4) determining the operation states of various electrolytic cell monomers by adopting a time-power double-line rotation control strategy based on the electrolytic cell power control quantity, thus making the electrolytic cell monomers operate in one of the four operating states in turn.

The application describes a method for operating an electrolyzer to generate hydrogen from water using an electrolysis reaction, supplied with power from an AC grid via an actively controlled rectifier circuit. The method includes operating the electrolyzer in a normal operating mode with an input voltage U.sub.EI above a no-load voltage U.sub.LL with predominantly ohmic behavior, operating the electrolyzer in a standby operating mode with an input voltage U.sub.EI below the no-load voltage U.sub.LL with predominantly capacitive behavior, and transitioning from the standby operating mode to the normal operating mode during a first transition duration Δt.sub.1, wherein the first transition duration Δt.sub.1 is reduced by keeping the input voltage U.sub.EI at the electrolyzer input during the standby operating mode above a first voltage threshold value U.sub.TH,1 different from 0 V. The application furthermore describes a connection circuit, an actively controlled rectifier circuit and an electrolysis system for performing the method.

The application describes a method for operating an electrolyzer to generate hydrogen from water using an electrolysis reaction, supplied with power from an AC grid via an actively controlled rectifier circuit. The method includes operating the electrolyzer in a normal operating mode with an input voltage U.sub.EI above a no-load voltage U.sub.LL with predominantly ohmic behavior, operating the electrolyzer in a standby operating mode with an input voltage U.sub.EI below the no-load voltage U.sub.LL with predominantly capacitive behavior, and transitioning from the standby operating mode to the normal operating mode during a first transition duration Δt.sub.1, wherein the first transition duration Δt.sub.1 is reduced by keeping the input voltage U.sub.EI at the electrolyzer input during the standby operating mode above a first voltage threshold value U.sub.TH,1 different from 0 V. The application furthermore describes a connection circuit, an actively controlled rectifier circuit and an electrolysis system for performing the method.

An apparatus for estimating electrical properties of an electrolyzer includes a data processing system for estimating electrical values, for example a membrane resistance, of the electrolyzer based on a difference voltage, a current, and an initial value and an attenuation time constant of a double-layer capacitance voltage of the electrolyzer during a shutdown of the electrolyzer. The difference voltage is a difference between a voltage of the electrolyzer and a total reversible voltage of the electrolyzer. The initial value and the attenuation time constant of the double-layer capacitance voltage are estimated based on values of the difference voltage when the current is zero and thus the difference voltage equals the double-layer capacitance voltage. The electrical values can be estimated even if a stepwise interruption of the current of the electrolyzer is not possible.

An apparatus for estimating electrical properties of an electrolyzer includes a data processing system for estimating electrical values, for example a membrane resistance, of the electrolyzer based on a difference voltage, a current, and an initial value and an attenuation time constant of a double-layer capacitance voltage of the electrolyzer during a shutdown of the electrolyzer. The difference voltage is a difference between a voltage of the electrolyzer and a total reversible voltage of the electrolyzer. The initial value and the attenuation time constant of the double-layer capacitance voltage are estimated based on values of the difference voltage when the current is zero and thus the difference voltage equals the double-layer capacitance voltage. The electrical values can be estimated even if a stepwise interruption of the current of the electrolyzer is not possible.

A novel polyfluorene-based ionomer, an anion exchange membrane, a method for preparing the polyfluorene-based ionomer, and a method for fabricating the anion exchange membrane are proposed. The polyfluorene-based ionomer contains no aryl ether bonds in the polymer backbone and includes piperidinium groups incorporated into the repeating units. The anion exchange membrane is fabricated from the polyfluorene-based ionomer. The anion exchange membrane has good thermal and chemical stability, excellent mechanical properties, and high ion conductivity. Due to these advantages, the anion exchange membrane can be applied as a membrane for an alkaline fuel cell and to a binder for an alkaline fuel cell or water electrolysis.

A device and method of controlling an electrode and electrolytic cell are provided, which independently utilizes clean energy with large power fluctuation range as an electrolysis power source for hydrogen and oxygen production. The basic number of electrodes is set by the minimum cut-in voltage value of fluctuating power sources such as wind or solar power. According to fluctuating power sources such as wind or solar power, the ratio of the minimum cut-in current and the reference current corresponding to the lowest cut-in voltage value sets the effective size of the electrodes to be connected in or cut out.

A device and method of controlling an electrode and electrolytic cell are provided, which independently utilizes clean energy with large power fluctuation range as an electrolysis power source for hydrogen and oxygen production. The basic number of electrodes is set by the minimum cut-in voltage value of fluctuating power sources such as wind or solar power. According to fluctuating power sources such as wind or solar power, the ratio of the minimum cut-in current and the reference current corresponding to the lowest cut-in voltage value sets the effective size of the electrodes to be connected in or cut out.

A method for obtaining a product by electrolysis, including: a) determining a set point for a production output by minimizing a first mathematical function, which depends on the production output and on a predicted product demand; b) determining respective set points for multiple process parameters by minimizing a second mathematical function, which depends on the set point for the production output determined in a), on the process parameters and on predicted degradation effects; c) determining respective set points for changes of multiple control parameters by minimizing a third mathematical function, which depends on the set points for the process parameters determined in b) and on the changes of the control parameters; and d) obtaining the product by performing the electrolysis using the set points for the changes of the control parameters determined in c).