TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Catalyst: The catalyst further comprises a support (preferably activated carbon). The catalyst comprises Re on the activated carbon; Re and Pd on the activated carbon; Rh and Re on the activated carbon; Ru and Re on the activated carbon; Mn and Re on the activated carbon; Re and Cu on the activated carbon; Ag on the activated carbon; Mn and Rh on the activated carbon; Mg on the activated carbon; Rh and Ir on the activated carbon; Ir and Pd on the activated carbon; or Rh on activated carbon (preferably Rh on activated carbon). The catalyst comprises the metal(s) ((0.1 to 35 wt./wt.%).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The method involves contacting the organotrihalosilane (I), with hydrogen, where the mole ratio of organotrihalosilane to hydrogen is 1:3 to 1:2300, in the presence of catalyst comprising a metal selected from Re; mixture comprising Re and at least one element selected from Pd, Ru, Mn, Cu, and Rh; a mixture comprising Ir and at least one element selected from Pd and Rh; Mn; a mixture comprising Mn and Rh; Ag; and Mg; at (300-800 degrees C, preferably 500-700 degrees C, or 700-800 degrees C for catalyst comprising Rh on activated carbon) to form the trihalosilane. The method further involves recovering the trihalosilane. The contacting is carried out at a reaction pressure of greater than 0 to 2900 kilopascals (gauge). The mole ratio of organotrihalosilane to hydrogen is (1:3 to 1:2300, or 0.01:1 to 10, preferably 1:43 to 1:300). The organotrihalosilane and hydrogen have a residence time of 0.01 second to 10 minutes. The contacting is performed in a reactor having a contact portion in contact with the organosilane and hydrogen, where the contact portion has an iron content of less than 20 wt.%. The method further involves activating the catalyst prior to contacting with hydrogen and organotrihalosilane in the presence of catalyst; making a dihalosilane in the contacting step, where the dihalosilane is of formula H2SiX'2; regenerating the catalyst after contacting with hydrogen and organotrihalosilane in the presence of the catalyst; and diluting hydrogen with a diluent gas, at a pressure of greater than 1380 to 3450 kilopascals (gauge). Preferred Definitions:    R'=methyl;    X'=Cl.    EXAMPLE - A trichlorosilane was formed using Re on carbon as follows. In flow reactor, catalyst (0.6 g) comprising Re (5.9 wt./wt.%) on carbon, was loaded into glass tube. Activation of catalyst was performed with 10 standard cm3 per minute (sccm) H2 at 450 degrees C for 15 hours. Then temperature of reactor was decreased to 200 degrees C and reaction was started by passing H2 through MeSiCl3 bubbler. Samples were taken from reaction stream and injected into gas chromatography (GC) for analysis using online switching valve. The reaction was run a reaction conditions of temperature of -15.2 degrees C, flow rate of hydrogen of 10 sccm, MeSiCl3 (0.2 sccm) bubbler temperature of 500 degrees C, and reaction time of 390 minutes. The catalyst activation and reaction were done without applying back pressure to system. The HSiCl3 (yield = 9.7%) was obtained.