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CO 2 is electrochemically reduced to CH 4 , C 2 H 4 , and alcohols in aqueous electrolytes at Cu electrode with high current density. CO 2 is initially reduced to adsorbed CO and further to hydrocarbons and alcohols. This paper describes macroscopic electrolytic reduction of CO at a Cu electrode in various electrolyte solutions in order to reveal the unique properties of Cu electrode in comparison with Fe and Ni electrodes. The reaction products from the Cu electrode are CH 4 , C 2 H 4 , C 2 H 5 OH, n-C 3 H 7 OH, CH 3 CHO, and C 2 H 5 CHO. Neither C 2 H 6 nor CH 3 OH is produced. CH 4 is favorably produced in aqueous KHCO 3 of high concentrations (e.g. 0.3 mol dm -3 ), whereas C 2 H 4 and C 2 H 5 OH are produced in dilute KHCO 3 solutions (0.03 mol dm -3 ). Such product selectivity is derived from the electrogenerated OH -in the cathodic reaction, as is the case in the CO 2 reduction. The partial current densities of CH 4 , C 2 H 4 , and C 2 H 5 OH are correlated with the electrode potential. Tafel relationships hold for C 2 H 4 and C 2 H 5 OH irrespective of pH. The partial current of CH 4 formation is proportional to proton activity and also follows the Tafel relationship. The transfer coefficients are 0.35 for C 2 H 4 formation and 1.33 for CH 4 formation. These facts indicate that the reaction paths of CH 4 and C 2 H 4 formations are separated at an early stage of CO reduction. Ethanol and n-propanol may be reduced from acetaldehyde and propionaldehyde intermediately formed in the reaction. The molecular reaction path is discussed with regard to these experimental results.

In this study, we mainly investigated the visual selectivity of hand-manipulation-related neurons in the anterior intraparietal area (area AIP) while the animal was grasping or fixating on three-dimensional (3D) objects of different geometric shapes, sizes, and orientations. We studied the activity of 132 task-related neurons during the hand-manipulation tasks in the light and in the dark, as well as during object fixation. Seventy-seven percent (101/132) of the hand-manipulation-related neurons were visually responsive, showing either lesser activity during manipulation in the dark than during that in the light (visual-motor neurons) or no activation in the dark (visual-dominant neurons). Of these visually responsive neurons, more than half (n = 66) responded during the object-fixation task (object-type). Among these, 55 were tested for their shape selectivity during the object-fixation task, and many (n = 25) were highly selective, preferring one particular shape of the six different shapes presented (ring, cube, cylinder, cone, sphere, and square plate). For 28 moderately selective object-type neurons, we performed multidimensional scaling (MDS) to examine how the neurons encode the similarity of objects. The results suggest that some moderately selective neurons responded preferentially to common geometric features shared by similar objects (flat, round, elongated, etc.). Moderately selective nonobject-type visually responsive neurons, which did not respond during object fixation, were found by MDS to be more closely related to the handgrip than to the object shape. We found a similar selectivity for handgrip in motor-dominant neurons that did not show any visual response. With regard to the size of the objects, 16 of 26 object-type neurons tested were selective for both size and shape, whereas 9 object-type neurons were selective for shape but not for size. Seven of 12 nonobject-type and all (8/8) of the motor-dominant neurons examined were selective for size, and almost all of them were also selective for objects. Many hand-manipulation-related neurons that preferred the plate and/or ring were selective for the orientation of the objects (17/20). These results suggest that the visual responses of object-type neurons represent the shape, size, and/or orientation of 3D objects, whereas those of the nonobject-type neurons probably represent the shape of the handgrip, grip size, or hand-orientation. The activity of motor-dominant neurons was also, in part, likely to represent these parameters of hand movement. This suggests that the dorsal visual pathway is concerned with the aspect of form, orientation, and/or size perception that is relevant for the visual control of movements.

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The electrochemical reduction of CO2 was studied with galvanostatic (5 mA cm−2) electrolysis at a copper electrode between 0 and 40 °C. The production of CH4 and C2H4 was confirmed by GC with 4 different columns. The faradaic efficiency of CH4 formation was about 65% at 0 °C and dropped with an increase of temperature, whereas that of C2H4 formation rose to ca. 20% at 40 °C.

Visual and motor properties of single neurons of monkey ventral premotor cortex (area F5) were studied in a behavioral paradigm consisting of four conditions: object grasping in light, object grasping in dark, object fixation, and fixation of a spot of light. The employed objects were six different three-dimensional (3-D) geometric solids. Two main types of neurons were distinguished: motor neurons (n = 25) and visuomotor neurons (n = 24). Motor neurons discharged in association with grasping movements. Most of them (n = 17) discharged selectively during a particular type of grip. Different objects, if grasped in similar way, determined similar neuronal motor responses. Visuomotor neurons also discharged during active movements, but, in addition, they fired also in response to the presentation of 3-D objects. The majority of visuomotor neurons (n = 16) showed selectivity for one or few objects. The response was present both in object grasping in light and in object fixation conditions. Visuomotor neurons that selectively discharged to the presentation of a given object discharged also selectively during grasping of that object. In conclusion, object shape is coded in F5 even when a response to that object is not required. The possible visual or motor nature of this object coding is discussed.

We traced the cortical connections of the anterior intraparietal (AIP) area, which is known to play a crucial role in visuomotor transformations for grasping. AIP displayed major connections with 1) areas of the inferior parietal lobule convexity, the rostral part of the lateral intraparietal area and the SII region; 2) ventral visual stream areas of the lower bank of the superior temporal sulcus and the middle temporal gyrus; and 3) the premotor area F5 and prefrontal areas 46 and 12. Additional connections were observed with the caudal intraparietal area and the ventral part of the frontal eye field. This study suggests that visuomotor transformations for object-oriented actions, processed in AIP, rely not only on dorsal visual stream information related to the object's physical properties but also on ventral visual stream information related to object identity. The identification of direct anatomical connections with the inferotemporal cortex suggests that AIP also has a unique role in linking the parietofrontal network of areas involved in sensorimotor transformations for grasping with areas involved in object recognition. Thus, AIP could represent a crucial node in a cortical circuit in which hand-related sensory and motor signals gain access to representations of object identity for tactile object recognition.

C02 is electrochemically reduced to CO in 0.5 M aqueous KHCOB solution at a gold electrode a t 18 "C, the reaction proceeding with markedly low overvoltage, starting at -0.8 V vs. normal hydrogen electrode (N.H.E.); the faradaic efficiency for CO formation is 91% a t -1.10 V vs. N.H.E. with a partial current of 3.7 mA cm-2, and the reaction probably proceeds via adsorbed intermediates.The cathodic reduction of C 0 2 at metal electrodes (Hg, Pb, Zn, Cd, Sn, and In) exclusively yields HC02-with high overvoltages in aqueous inorganic salt solutions. 1 We previously reported the electroreduction of C02 at various metal cathodes in KHC03 aqueous solution.2 Au and Ag cathodes gave CO as the major product. CH4 and C2H4 were produced at Cu cathodes with high current efficiencies of 5-10 mA cm-2. We now describe the effective electroreduction of C02 to CO at an Au cathode.An Au electrode (99.99% purity), size 20 X 20 x 0.5 mm, welded to a gold wire (0.5 mm diameter), was etched with aqua regia for 1 min at ambient temperature, and then rinsed three times with doubly distilled water in an ultrasonic cleaning bath. A three-compartment Pyrex cell was employed in which two anode compartments faced each side of the cathode. The cathode compartment (36 mm inner diameter) was separated from the two anodes with sheets of cation exchange membrane (Selemion). The cathode was placed roughly at the centre of the electrolyte. The potential of the cathode was measured with respect to an Ag/AgCl electrode. The electrode potential was corrected for the IR drop between the Luggin capillary tip and the cathode. The aqueous electrolyte (0.5 M KHC03) was purified by pre-electrolysis with a 30 x 20 mm Pt black cathode at 2 X 10-2 mA cm-2