Electrochemical synthesis method and device

Abstract

The present invention relates to a method for producing at least one product by electrochemical synthesis on a directly electrically-heated working electrode ( 1 ), in which at least one educt reacts on the heated working electrode ( 1 ) to the at least one product. The invention also relates to the use of a directly electrically-heated working electrode ( 1 ) for the electrochemical synthesis of at least one product. The invention relates in particular to a working electrode ( 1 ), particularly in the form of a three-dimensional, preferably conical spiral, designed for the electrochemical synthesis. Another object of the invention is the synthesis/regeneration of an enzymatic cofactor on a working electrode ( 1 ) according to the invention.

1 . A process for producing at least one product by electrochemical synthesis on a directly electrically heated working electrode ( 1 ) in which at least one educt reacts on the heated working electrode ( 1 ) to the at least one product. 
     
     
         2 . The use of a directly electrically heated working electrode ( 1 ) for the electrochemical synthesis of at least one product, in which at least one educt reacts on the heated working electrode ( 1 ) to the at least one product. 
     
     
         3 . The process of  claim 1 , wherein the working electrode ( 1 ) is directly heated by means of a symmetrical arrangement with a heating current in the form of an alternating current, wherein the symmetrical contacting preferably occurs via a bridge circuit ( 2 ). 
     
     
         4 . The process of  claim 1 , wherein the electrochemically active surface area of the working electrode ( 1 ) comprises at least 1×10 −6  m 2 , preferably 1×10 −5  m 2  or 1×10 −4  m 2 . 
     
     
         5 . The process of  claim 1 , wherein the reaction is selected from the group consisting of oxidation, reduction, protonation, deprotonation, substitution, hydrogenation, dehydrogenation, condensation, hydrolysis, addition, cleavage, cyclization, dimerization, polymerization and elimination. 
     
     
         6 . The process of  claim 1 , wherein the product is selected from the group consisting of a protein comprising a nitro group, gluconic acid, sorbitol, D-arabinose, adiponitrile, a regenerated cofactor such as NAD+ or NADP+ and a product which is unstable at the reaction temperature on the working electrode ( 1 ). 
     
     
         7 . The process of  claim 1 , wherein the reaction of the at least one educt to the at least one product is enzymatically catalyzed, wherein optionally the enzyme and/or a cofactor is immobilized on the heated working electrode ( 1 ). 
     
     
         8 . The process according to  claim 1 ,
 wherein a heating current in the form of an alternating current with a frequency of at least 1 kHz, preferably at least 20 kHz, more preferably at least 50 kHz or at least 100 kHz is used for heating the working electrode ( 1 ), and/or   wherein the temperature of the working electrode ( 1 ) is increased pulse-like for up to 250 ms above the boiling point of the electrolytes surrounding the electrode.   
     
     
         9 . A device comprising two insulated conductors ( 3 ) which are connected to one another via a working electrode ( 1 ) which is thinner in relation to the conductors, wherein the working electrode is a wire of an electrode material selected from the group comprising gold, platinum, copper, nickel, stainless steel, lead, Hg-amalgams, indium-doped tin oxide and carbon, wherein the working electrode ( 1 ) has the form of a three-dimensional spiral. 
     
     
         10 . The device according to  claim 9 , wherein the spiral forms a conical spiral, preferably a conical Archimedean spiral or an Archimedean spiral coil, a loxodrome or a section of such a spiral. 
     
     
         11 . A device comprising two insulated conductors ( 3 ) which are connected to one another via a plurality of working electrodes which are thinner in relation to the insulated conductors, wherein the working electrodes ( 1 ) are composed of an electrode material selected from the group comprising gold, platinum, copper, nickel, noble steel, lead, Hg-amalgams, indium doped tin oxide and carbon, wherein the working electrodes ( 1 ) are arranged so that no vertical superimposition takes place and that they
 (a) are preferably essentially parallel to one another, and/or   (b) preferably extend from a lower contact point ( 5 ) with one of the insulated conductors ( 3 ) to an upper contact point ( 6 ) offset vertically and optionally horizontally with the other insulated conductor ( 3 ), wherein the working electrodes ( 1 ) extend outwardly from the lower contact point ( 5 ), extend obliquely upwards in an intermediate section and extend inwards in an upper section towards the upper contact point ( 6 ), wherein the inclination in the middle section is arranged so that no vertical superimposition of the working electrode sections ( 1 ) or the working electrodes ( 1 ) occurs.   
     
     
         12 . The device according to  claim 9 , wherein the working electrode ( 1 ) is stabilized by an insulating carrier ( 7 ),
 wherein the insulating carrier ( 7 ) is preferably a cage or a grid, and/or   wherein the insulating carrier ( 7 ) is preferably made of an insulating material selected from the group comprising glass, ceramic or plastic, e.g. Polytetrafluoroethylene (PTFE).   
     
     
         13 . The device according to  claim 9 , wherein the working electrode has a surface area of at least 1×10 −5 m 2 , preferably 5×10 −5 m 2  or 7×10 −5 m 2 , and/or a diameter of 0.1-5 mm and/or a length of 2.5-100 mm and/or a resistance of 0.5-20 Ohm. 
     
     
         14 . The device according to  claim 9 , wherein the working electrode ( 1 ) is directly heated by means of a symmetrical arrangement with a heating current in the form of an alternating current, wherein the symmetrical contacting preferably occurs via a bridge circuit ( 2 ). 
     
     
         15 . The device according to  claim 9 , wherein the counterelectrode is arranged with a distance of at least 1 mm, preferably at least 5 mm, relative to the working electrode, such that the thermal convection around and above the working electrode does not lead to a mixing of the space around the counterelectrode, preferably the counterelectrode is located under the working electrode. 
     
     
         16 . The process of  claim 1 , wherein the reaction proceeds at the directly heated working electrode of a device comprising two insulated conductors ( 3 ) which are connected to one another via a working electrode ( 1 ) which is thinner in relation to the conductors, wherein the working electrode is a wire of an electrode material selected from the group comprising gold, platinum, copper, nickel, stainless steel, lead, Hg-amalgams, indium-doped tin oxide and carbon, wherein the working electrode ( 1 ) has the form of a three-dimensional spiral. 
     
     
         17 . A process for the synthesis or regeneration of a cofactor of an enzymatic reaction, wherein the synthesis or regeneration takes place on a directly electrically heatable working electrode, preferably on the directly heated working electrode of a device according to  claim 9 . 
     
     
         18 . The use of  claim 2 , wherein the working electrode ( 1 ) is directly heated by means of a symmetrical arrangement with a heating current in the form of an alternating current, wherein the symmetrical contacting preferably occurs via a bridge circuit ( 2 ). 
     
     
         19 . The use of  claim 2 , wherein the electrochemically active surface area of the working electrode ( 1 ) comprises at least 1×10 −6  m 2 , preferably 1×10 −5  m 2  or 1×10 −4  m 2 . 
     
     
         20 . The use of  claim 2 , wherein the reaction is selected from the group consisting of oxidation, reduction, protonation, deprotonation, substitution, hydrogenation, dehydrogenation, condensation, hydrolysis, addition, cleavage, cyclization, dimerization, polymerization and elimination. 
     
     
         21 . The use of  claim 2 , wherein the product is selected from the group consisting of a protein comprising a nitro group, gluconic acid, sorbitol, D-arabinose, adiponitrile, a regenerated cofactor such as NAD+ or NADP+ and a product which is unstable at the reaction temperature on the working electrode ( 1 ). 
     
     
         22 . The use of  claim 2 , wherein the reaction of the at least one educt to the at least one product is enzymatically catalyzed, wherein optionally the enzyme and/or a cofactor is immobilized on the heated working electrode ( 1 ). 
     
     
         23 . The use according to  claim 2 ,
 wherein a heating current in the form of an alternating current with a frequency of at least 1 kHz, preferably at least 20 kHz, more preferably at least 50 kHz or at least 100 kHz is used for heating the working electrode ( 1 ), and/or   wherein the temperature of the working electrode ( 1 ) is increased pulse-like for up to 250 ms above the boiling point of the electrolytes surrounding the electrode.   
     
     
         24 . The use of  claim 2 , wherein the reaction proceeds at the directly heated working electrode of a device comprising two insulated conductors ( 3 ) which are connected to one another via a working electrode ( 1 ) which is thinner in relation to the conductors, wherein the working electrode is a wire of an electrode material selected from the group comprising gold, platinum, copper, nickel, stainless steel, lead, Hg-amalgams, indium-doped tin oxide and carbon, wherein the working electrode ( 1 ) has the form of a three-dimensional spiral.