The converter comprises an inverter powered by a DC current source. The metal residue inhibitor is selected from the group of compounds having the following formulas:and combinations thereof,wherein R1, R2, R3, and R4 are independently selected from H, C1-C6 alkyl, C2-C6 alkenyl, and C2-C6 alkylidyne; and R5, R6, R7, R8, R9, and R10 are independently selected from H and C1-C6 alkyl. Expiration of the acknowledgment timer indicates a missing packet in the second direction. Applying a limited current to a sourcedrain region during an erase operation can cause the sourcedrain region and a floating gate to rise together and avoid band-to-band tunneling and resulting hole injection into the floating gate. Preferably the method is carried out to produce propylene with greater than 50% specificity, more preferably, the propylene to butylene ratio is at least 2:1 or a propylene to ethylene ratio of at least 4:1.