News of the Week tion Division for consideration. The end result was last week's complete approval of the patent. U.S. patents were awarded in 1985 to both Biogen and Hoffmann-La Roche, which developed α-interfer ons with Genentech. Roche and Schering-Plough, in what was called the defusing of a potentially major biotechnology patent fight, agreed not to sue each other over manufac turing and sales of α-interferons worldwide, except in Japan.
The α-interferon market is shared by Roche and Schering-Plough, which market their products as Roferon-A and Intron A, respectively. Intron A sales by Schering-Plough, which says it has a majority share of the world market, nearly doubled between 1988 and 1989 to about $90 million. Analysts have projected that the company's worldwide sales for α-interferon will exceed $150 million in 1990. Ann Thayer
Catalyst converts methane to C> hydrocarbons A new catalyst that converts meth ane to C2 hydrocarbons, with nearly 100% selectivity at atmospheric pres sure and moderate temperatures, has been developed at Lawrence Berke ley Laboratory. The reaction appears to be strictly catalytic and there are no carbon oxides formed, thereby ruling out gas-phase reactions. At present, the per-pass conversion is about 10% and steam is required in the conversion. Described recently in Catalysis Let ters [6, 255 (1990)], the work was car ried out at Lawrence Berkeley Labo ratory's Center for Advanced Mate rials by a research team that included chemists Heinz Heinemann, Gabor A. Somorjai, Pedro Pereira, and S. H. Lee. It was funded by the U.S. Department of Energy's Office of Fossil Energy. Direct con version of methane to higher hydro carbons, particularly light olefins, is being pursued in catalytic research labs around the world. The new catalyst is a calcium, nickel, and potassium mixed oxide system requiring great care in prep aration. Slight variations in the preparation produce materials with very different properties. The best experimental runs were done at 600 °C and 1 atm total pressure. Meth ane conversion was 10%, and the se lectivity to C2 hydrocarbons was greater than 97%. The catalyst sur face composition appears to be Ca:Ni:K in a ratio of 2:1:0.1. A mechanism for direct methane conversion that has been proposed in the literature for previous tech niques is one of methane oxidative dimerization in the presence of alka li-earth oxide at high temperatures. 8
November 26, 1990 C&EN
Nanode forms when glass coats sharpened Pt or Pt-Ir wire but leaves tip exposed
The active species here is the meth yl free radical that reacts almost ex most of the wire with an insulating clusively in the gas phase. For ther glass layer but leaving an exposed modynamic reasons, carbon oxides area of controllable, variable size at form. the tip. "Think of the electrode as a In the new reaction system, a dif pencil," says Lewis, "with pencil inferent mechanism is at work. The re sulation everywhere but at the very search team believes the active ad tip." sorbed species from methane forms The tiniest such electrodes are "so on the catalyst surface at the low small we can't find them with a temperatures employed. Conse scanning electron microscope," says quently, there is no carbon oxide Lewis, "so we can't measure their formation. size directly." Instead, the researchThe reacting system typically in ers estimate the size of the smallest cludes methane, oxygen, and steam nanodes mathematically from voltain the ratio of 3:1:6.5. The role of the metric data. steam is still not understood and is The nanodes extend the range of under study. measurable electron-transfer rate Joseph Haggin constants to values that are two orders of magnitude faster than those accessible with other techniques. Compared with a nanode of 10-A raElectrodes a few atoms dius, a hypothetical electrode composed of a single platinum atom wide made at Caltech would be capable of measuring rate Electrodes as small as 10 Â in radi- constants that are only about six us—the width of about four plati- times faster. num atoms—have been fabricated Nanodes might also prove advanby Reginald M. Penner, Michael J. tageous in several other applicaHeben, Teresa L. Longin, and tions. They could make it possible to Nathan S. Lewis of California Insti- observe chemical processes on a tute of Technology [Science, 250, more localized scale and to deposit 1118 (1990)]. narrower metal lines on semiconUltramicroelectrodes used in elec- ductor surfaces, using scanning mitrochemistry have been made as croscopy techniques. In neurophysismall as 0.1 μια (1000 Â) in radius. ological studies, they could make it However, the new electrodes, called easier to detect neurotransmitters in nanodes, are as much as two orders single nerve cells. In electrochemiof magnitude smaller. cal experiments, smaller electrodes To make the nanodes, Lewis and provide better rejection of backcoworkers use a cyanide solution to ground currents. In addition, naetch a platinum or platinum-iridium nodes might provide higher resoluwire to a sharp point. The sharp- tion flow detection for chromatograened wire is then drawn through a phy and electrophoresis. droplet of molten glass, coating Stu Borman
