Although both the ECB and Federal Reserve are central banks, they are much different in their approach to managing their respective economies. The Fed's mandate includes both promoting growth and controlling inflation, while the ECB is really only designed to mitigate inflation. Thus, the ECB is not equipped to act in a speedy fashion as the Fed did in response to our financial crisis. (See the article here, Wall Street Journal.)
Dolvin, Steven D., "The ECB Is NOT the Fed" (2012). All Chapters. 12.