His research specialty is molecular sieve zeolites -- materials used in industrial pollution control processes. He has numerous publications on molecular sieves and holds patents on their synthesis and application.
Prior to his position at SDSU, Hayhurst had been Dean of the College of Engineering at the University of South Alabama in Mobile, Alabama since January 1992. And before his position at the University of South Alabama, Hayhurst served as chair of the Department of Chemical Engineering at Cleveland State University.

San Diego State University's College of Engineering is home to eight degree programs (Aerospace Engineering, Bioengineering, Civil Engineering, Construction Engineering, Environmental Engineering, Electrical Engineering, Computer Engineering and Mechanical Engineering) and six research centers. It has more than 1,800 students and approximately 50 full-time faculty. In 2001-2002 the college received more than $2.3 million in external grants and contracts for research and program administration, more than quadruple the amount it was awarded in 1996-97.

Hayhurst and his wife, Mari, raise and show AKC champion Great Danes and Whippets.