Borohydride has been considered as a potential fuel for the fuel cell application due to its high energy density. A DBFC (direct borohydride fuel cell) is an electrochemical device that converts chemical energy stored in borohydride and oxidant directly to electrical energy as long as the fuel and oxidant is supplied. One of the main problems encountered in a DBFC is the simultaneous hydrolysis of BR4- at the anode surface. The hydrolysis decreases the fuel utilization and fuel cell performance, since hydrogen bubbles hinder the contact of catalyst with reactant. This study investigates the effect of operating conditions (cell temperature, borohydride concentration, flow rates of fuel and oxidant) on DBFC performance by RSM (response surface methodology). PtRu/C is used as the anode catalyst to systematically investigate the effect of hydrogen evolution rate on the fuel cell performance. The maximum power density is obtained at 80 degrees C fuel cell temperature, 0.5 M NaBH4 concentration, 5 cm(3) min(-1) flow of anolyte and 100 cm(3) min(-1) flow of oxygen. (C) 2014 Elsevier Ltd. All rights reserved.